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Sample records for abl kinase inhibitors

  1. [Mechanisms of resistance to BCR-ABL kinase inhibitors].

    PubMed

    Diamond, Joana; da Silva, Maria Gomes

    2013-01-01

    Since the introduction of imatinib mesylate for the treatment of chronic myeloid leukaemia, impressive clinical responses were observed in the majority of patients in chronic phase. However, not all patients experience an optimal response to imatinib mesylate or even to the more potent, second generation tyrosine kinase inhibitors. Furthermore, responses are not sustained in a number of patients, and it is yet unclear whether the inhibitors can be safely discontinued in patients who achieve long-term remission. The emergence of resistance to second generation tyrosine kinase inhibitors has become a significant problem that led to extensive studies on the causal mechanisms. This review will describe our current state of knowledge on why and how chronic myeloid leukaemia cells can develop resistance to second generation tyrosine kinase inhibitors.

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

    PubMed Central

    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. Opening the door to the development of novel Abl kinase inhibitors.

    PubMed

    Bezerra Morais, Pedro Alves; Daltoé, Renata Dalmaschio; Paula, Heberth de

    2016-10-24

    The discovery of the importance of kinase activity and its relationship to the emergence and proliferation of cancer cells, due to changes in normal physiology, opened a remarkable pathway for the treatment of chronic myelogenous leukemia through intense search of drug candidates. Six Abl kinase inhibitors have received the US FDA approval as chronic myelogenous leukemia treatment, and continuous efforts in obtaining new, more effective and selective molecules are being carried out. Herein we discuss the mechanisms of Abl inhibition, structural features and ligand/protein interactions that are important for the design of new Abl kinase inhibitors. This review provides a broad overview of binding mode predictions, through molecular docking, which can be an approach to discover novel Abl kinase inhibitors.

  4. Novel N9-arenethenyl purines as potent dual Src/Abl tyrosine kinase inhibitors.

    PubMed

    Wang, Yihan; Shakespeare, William C; Huang, Wei-Sheng; Sundaramoorthi, Raji; Lentini, Scott; Das, Sasmita; Liu, Shuangying; Banda, Geeta; Wen, David; Zhu, Xiaotian; Xu, Qihong; Keats, Jeffrey; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Mark I; Russian, Karin; Dalgarno, David; Clackson, Tim; Sawyer, Tomi K

    2008-09-01

    Novel N(9)-arenethenyl purines, optimized potent dual Src/Abl tyrosine kinase inhibitors, are described. The key structural feature is a trans vinyl linkage at N(9) on the purine core which projects hydrophobic substituents into the selectivity pocket at the rear of the ATP site. Their synthesis was achieved through a Horner-Wadsworth-Emmons reaction of N(9)-phosphorylmethylpurines and substituted benzaldehydes or Heck reactions between 9-vinyl purines and aryl halides. Most compounds are potent inhibitors of both Src and Abl kinase, and several possess good oral bioavailability.

  5. Novel Src/Abl tyrosine kinase inhibitor bosutinib suppresses neuroblastoma growth via inhibiting Src/Abl signaling

    PubMed Central

    Bieerkehazhi, Shayahati; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Zhang, Huiyuan; Vasudevan, Sanjeev A.; Woodfield, Sarah E.; Tao, Ling; Yi, Joanna S.; Muscal, Jodi A.; Pang, Jonathan C.; Guan, Shan; Zhang, Hong; Nuchtern, Jed G.; Li, Hui; Li, Huiwu; Yang, Jianhua

    2017-01-01

    Neuroblastoma (NB) is the most common extracranial solid tumor in children. Aberrant activation of the non-receptor tyrosine kinases Src and c-Abl contributes to the progression of NB. Thus, targeting these kinases could be a promising strategy for NB therapy. In this paper, we report that the potent dual Src/Abl inhibitor bosutinib exerts anti-tumor effects on NB. Bosutinib inhibited NB cell proliferation in a dose-dependent manner and suppressed colony formation ability of NB cells. Mechanistically, bosutinib effectively decreased the activity of Src/Abl and PI3K/AKT/mTOR, MAPK/ERK, and JAK/STAT3 signaling pathways. In addition, bosutinib enhanced doxorubicin (Dox)- and etoposide (VP-16)-induced cytotoxicity in NB cells. Furthermore, bosutinib demonstrated anti-tumor efficacy in an orthotopic xenograft NB mouse model in a similar mechanism as of that in vitro. In summary, our results reveal that Src and c-Abl are potential therapeutic targets in NB and that the novel Src/Abl inhibitor bosutinib alone or in combination with other chemotherapeutic agents may be a valuable therapeutic option for NB patients. PMID:27903968

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

    SciTech Connect

    Okabe, Seiichi 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.

  7. Combination therapy with copanlisib and ABL tyrosine kinase inhibitors against Philadelphia chromosome-positive resistant cells

    PubMed Central

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

    2016-01-01

    ABL tyrosine kinase inhibitor (TKI) therapy has improved the survival of patients with Philadelphia (Ph) chromosome-positive leukemia. However, ABL TKIs cannot eradicate leukemia stem cells. Therefore, new therapeutic approaches for Ph-positive leukemia are needed. Aberrant activation of phosphoinositide 3-kinase (PI3K) signaling is important for the initiation and maintenance of human cancers. Copanlisib (BAY80-6946) is a potent inhibitor of PI3Kα and PI3K-δ. Here we investigated the efficacy of combination therapy of copanlisib with an ABL TKI (imatinib, nilotinib, or ponatinib) using BCR-ABL-positive cells. Although the effects of the ABL TKI treatment were reduced in the presence of the feeder cell line, HS-5, copanlisib inhibited cell growth. Upon combining ABL TKI and copanlisib, cell growth was reduced. Ponatinib and copanlisib combined therapy reduced tumor volume and increased survival in mouse allograft models, respectively. These results indicate that the PI3Kα and -δ inhibitors overcame the chemoprotective effects of the feeder cells and enhanced ABL TKI cytotoxicity. Thus, co-treatment with ABL TKI and copanlisib may be a powerful strategy against ABL TKI-resistant cells, including those harboring the related T315I mutation. PMID:27437766

  8. Combination therapy with copanlisib and ABL tyrosine kinase inhibitors against Philadelphia chromosome-positive resistant cells.

    PubMed

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

    2016-08-16

    ABL tyrosine kinase inhibitor (TKI) therapy has improved the survival of patients with Philadelphia (Ph) chromosome-positive leukemia. However, ABL TKIs cannot eradicate leukemia stem cells. Therefore, new therapeutic approaches for Ph-positive leukemia are needed. Aberrant activation of phosphoinositide 3-kinase (PI3K) signaling is important for the initiation and maintenance of human cancers. Copanlisib (BAY80-6946) is a potent inhibitor of PI3Kα and PI3K-δ. Here we investigated the efficacy of combination therapy of copanlisib with an ABL TKI (imatinib, nilotinib, or ponatinib) using BCR-ABL-positive cells. Although the effects of the ABL TKI treatment were reduced in the presence of the feeder cell line, HS-5, copanlisib inhibited cell growth. Upon combining ABL TKI and copanlisib, cell growth was reduced. Ponatinib and copanlisib combined therapy reduced tumor volume and increased survival in mouse allograft models, respectively. These results indicate that the PI3Kα and -δ inhibitors overcame the chemoprotective effects of the feeder cells and enhanced ABL TKI cytotoxicity. Thus, co-treatment with ABL TKI and copanlisib may be a powerful strategy against ABL TKI-resistant cells, including those harboring the related T315I mutation.

  9. A Cell-Based Assay for Measuring Endogenous BcrAbl Kinase Activity and Inhibitor Resistance

    PubMed Central

    Ouellette, Steven B.; Noel, Brett M.; Parker, Laurie L.

    2016-01-01

    Kinase enzymes are an important class of drug targets, particularly in cancer. Cell-based kinase assays are needed to understand how potential kinase inhibitors act on their targets in a physiologically relevant context. Current cell-based kinase assays rely on antibody-based detection of endogenous substrates, inaccurate disease models, or indirect measurements of drug action. Here we expand on previous work from our lab to introduce a 96-well plate compatible approach for measuring cell-based kinase activity in disease-relevant human chronic myeloid leukemia cell lines using an exogenously added, multi-functional peptide substrate. Our cellular models natively express the BcrAbl oncogene and are either sensitive or have acquired resistance to well-characterized BcrAbl tyrosine kinase inhibitors. This approach measures IC50 values comparable to established methods of assessing drug potency, and its robustness indicates that it can be employed in drug discovery applications. This medium-throughput assay could bridge the gap between single target focused, high-throughput in vitro assays and lower-throughput cell-based follow-up experiments. PMID:27598410

  10. Combination of bortezomib and mitotic inhibitors down-modulate Bcr-Abl and efficiently eliminates tyrosine-kinase inhibitor sensitive and resistant Bcr-Abl-positive leukemic cells.

    PubMed

    Bucur, Octavian; Stancu, Andreea Lucia; Goganau, Ioana; Petrescu, Stefana Maria; Pennarun, Bodvael; Bertomeu, Thierry; Dewar, Rajan; Khosravi-Far, Roya

    2013-01-01

    Emergence of resistance to Tyrosine-Kinase Inhibitors (TKIs), such as imatinib, dasatinib and nilotinib, in Chronic Myelogenous Leukemia (CML) demands new therapeutic strategies. We and others have previously established bortezomib, a selective proteasome inhibitor, as an important potential treatment in CML. Here we show that the combined regimens of bortezomib with mitotic inhibitors, such as the microtubule-stabilizing agent Paclitaxel and the PLK1 inhibitor BI2536, efficiently kill TKIs-resistant and -sensitive Bcr-Abl-positive leukemic cells. Combined treatment activates caspases 8, 9 and 3, which correlate with caspase-induced PARP cleavage. These effects are associated with a marked increase in activation of the stress-related MAP kinases p38MAPK and JNK. Interestingly, combined treatment induces a marked decrease in the total and phosphorylated Bcr-Abl protein levels, and inhibits signaling pathways downstream of Bcr-Abl: downregulation of STAT3 and STAT5 phosphorylation and/or total levels and a decrease in phosphorylation of the Bcr-Abl-associated proteins CrkL and Lyn. Moreover, we found that other mitotic inhibitors (Vincristine and Docetaxel), in combination with bortezomib, also suppress the Bcr-Abl-induced pro-survival signals and result in caspase 3 activation. These results open novel possibilities for the treatment of Bcr-Abl-positive leukemias, especially in the imatinib, dasatinib and nilotinib-resistant CML cases.

  11. Combination of Bortezomib and Mitotic Inhibitors Down-Modulate Bcr-Abl and Efficiently Eliminates Tyrosine-Kinase Inhibitor Sensitive and Resistant Bcr-Abl-Positive Leukemic Cells

    PubMed Central

    Goganau, Ioana; Petrescu, Stefana Maria; Pennarun, Bodvael; Bertomeu, Thierry; Dewar, Rajan; Khosravi-Far, Roya

    2013-01-01

    Emergence of resistance to Tyrosine-Kinase Inhibitors (TKIs), such as imatinib, dasatinib and nilotinib, in Chronic Myelogenous Leukemia (CML) demands new therapeutic strategies. We and others have previously established bortezomib, a selective proteasome inhibitor, as an important potential treatment in CML. Here we show that the combined regimens of bortezomib with mitotic inhibitors, such as the microtubule-stabilizing agent Paclitaxel and the PLK1 inhibitor BI2536, efficiently kill TKIs-resistant and -sensitive Bcr-Abl-positive leukemic cells. Combined treatment activates caspases 8, 9 and 3, which correlate with caspase-induced PARP cleavage. These effects are associated with a marked increase in activation of the stress-related MAP kinases p38MAPK and JNK. Interestingly, combined treatment induces a marked decrease in the total and phosphorylated Bcr-Abl protein levels, and inhibits signaling pathways downstream of Bcr-Abl: downregulation of STAT3 and STAT5 phosphorylation and/or total levels and a decrease in phosphorylation of the Bcr-Abl-associated proteins CrkL and Lyn. Moreover, we found that other mitotic inhibitors (Vincristine and Docetaxel), in combination with bortezomib, also suppress the Bcr-Abl-induced pro-survival signals and result in caspase 3 activation. These results open novel possibilities for the treatment of Bcr-Abl-positive leukemias, especially in the imatinib, dasatinib and nilotinib-resistant CML cases. PMID:24155950

  12. Discovery of 2-Acylaminothiophene-3-Carboxamides as Multitarget Inhibitors for BCR-ABL Kinase and Microtubules.

    PubMed

    Cao, Ran; Wang, Yanli; Huang, Niu

    2015-11-23

    The emergence of drug resistance of the BCR-ABL kinase inhibitor imatinib, especially toward the T315I gatekeeper mutation, poses a great challenge to targeted therapy in treating chronic myeloid leukemia (CML) patients. To discover novel inhibitors against drug-resistant CML bearing T315I mutation, we applied a physics-based hierarchical virtual screening approach to dock a large chemical library against ATP binding pockets of both wild-type (WT) and T315I mutant ABL kinases in a combinatorial fashion. This strategy automatically resulted in 87 compounds satisfying structural and energetic criteria of both WT and T315I mutant kinases. Among them, nine compounds, which share a common thiophene-based scaffold and adopt similar binding poses, were chosen for experimental testing and one of them was shown to have low micromolar inhibition activities against both WT and mutant ABL kinases. Structure-activity relationship analysis with a series of structural modifications based on 2-acylaminothiophene-3-carboxamide scaffold supports our predicted binding mode. Interestingly, the same chemical scaffold was also enriched in our previous virtual screening campaign against colchicine site of microtubules using the same computational protocol, which suggests our virtual screening strategy is capable of discovering small-molecule ligands targeting distinct protein binding sites without sharing any sequential and structural similarity. Furthermore, the multitarget inhibition activity of this class of compounds was assessed in cellular experiments. We expect that the 2-acylaminothiophene-3-carboxamide scaffold may serve as a promising starting point for developing multitarget inhibitors in cancer treatment by targeting both kinases and microtubules.

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

    SciTech Connect

    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

    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.

  14. Activity of the Aurora kinase inhibitor VX-680 against Bcr/Abl-positive acute lymphoblastic leukemias.

    PubMed

    Fei, Fei; Stoddart, Sonia; Groffen, John; Heisterkamp, Nora

    2010-05-01

    The emergence of resistance to tyrosine kinase inhibitors due to point mutations in Bcr/Abl is a challenging problem for Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) patients, especially for those with the T315I mutation, against which neither nilotinib or dasatinib shows significant activity. VX-680 is a pan-Aurora kinase inhibitor active against all Bcr/Abl proteins but has not been extensively examined in preclinical models of Ph-positive ALL. Here, we have tested VX-680 for the treatment of Bcr/Abl-positive ALL when leukemic cells are protected by the presence of stroma. Under these conditions, VX-680 showed significant effects on primary human Ph-positive ALL cells both with and without the T315I mutation, including ablation of tyrosine phosphorylation downstream of Bcr/Abl, decreased viability, and induction of apoptosis. However, drug treatment of human Ph-positive ALL cells for 3 days followed by drug removal allowed the outgrowth of abnormal cells 21 days later, and on culture of mouse Bcr/Abl ALL cells on stroma with lower concentrations of VX-680, drug-resistant cells emerged. Combined treatment of human ALL cells lacking the T315I mutation with both VX-680 and dasatinib caused significantly more cytotoxicity than each drug alone. We suggest that use of VX-680 together with a second effective drug as first-line treatment for Ph-positive ALL is likely to be safer and more useful than second-line treatment with VX-680 as monotherapy for drug-resistant T315I Ph-positive ALL.

  15. 3D QSAR models built on structure-based alignments of Abl tyrosine kinase inhibitors.

    PubMed

    Falchi, Federico; Manetti, Fabrizio; Carraro, Fabio; Naldini, Antonella; Maga, Giovanni; Crespan, Emmanuele; Schenone, Silvia; Bruno, Olga; Brullo, Chiara; Botta, Maurizio

    2009-06-01

    Quality QSAR: A combination of docking calculations and a statistical approach toward Abl inhibitors resulted in a 3D QSAR model, the analysis of which led to the identification of ligand portions important for affinity. New compounds designed on the basis of the model were found to have very good affinity for the target, providing further validation of the model itself.The X-ray crystallographic coordinates of the Abl tyrosine kinase domain in its active, inactive, and Src-like inactive conformations were used as targets to simulate the binding mode of a large series of pyrazolo[3,4-d]pyrimidines (known Abl inhibitors) by means of GOLD software. Receptor-based alignments provided by molecular docking calculations were submitted to a GRID-GOLPE protocol to generate 3D QSAR models. Analysis of the results showed that the models based on the inactive and Src-like inactive conformations had very poor statistical parameters, whereas the sole model based on the active conformation of Abl was characterized by significant internal and external predictive ability. Subsequent analysis of GOLPE PLS pseudo-coefficient contour plots of this model gave us a better understanding of the relationships between structure and affinity, providing suggestions for the next optimization process. On the basis of these results, new compounds were designed according to the hydrophobic and hydrogen bond donor and acceptor contours, and were found to have improved enzymatic and cellular activity with respect to parent compounds. Additional biological assays confirmed the important role of the selected compounds as inhibitors of cell proliferation in leukemia cells.

  16. Inhibition of Aurora kinase B is important for biologic activity of the dual inhibitors of BCR-ABL and Aurora kinases R763/AS703569 and PHA-739358 in BCR-ABL transformed cells.

    PubMed

    Illert, Anna L; Seitz, Anna K; Rummelt, Christoph; Kreutmair, Stefanie; Engh, Richard A; Goodstal, Samantha; Peschel, Christian; Duyster, Justus; von Bubnoff, Nikolas

    2014-01-01

    ABL tyrosine kinase inhibitors (TKI) like Imatinib, Dasatinib and Nilotinib are the gold standard in conventional treatment of CML. However, the emergence of resistance remains a major problem. Alternative therapeutic strategies of ABL TKI-resistant CML are urgently needed. We asked whether dual inhibition of BCR-ABL and Aurora kinases A-C could overcome resistance mediated by ABL kinase mutations. We therefore tested the dual ABL and Aurora kinase inhibitors PHA-739358 and R763/AS703569 in Ba/F3- cells ectopically expressing wild type (wt) or TKI-resistant BCR-ABL mutants. We show that both compounds exhibited strong anti-proliferative and pro-apoptotic activity in ABL TKI resistant cell lines including cells expressing the strongly resistant T315I mutation. Cell cycle analysis indicated polyploidisation, a consequence of continued cell cycle progression in the absence of cell division by Aurora kinase inhibition. Experiments using drug resistant variants of Aurora B indicated that PHA-739358 acts on both, BCR-ABL and Aurora Kinase B, whereas Aurora kinase B inhibition might be sufficient for the anti-proliferative activity observed with R763/AS703569. Taken together, our data demonstrate that dual ABL and Aurora kinase inhibition might be used to overcome ABL TKI resistant CML.

  17. Inhibition of Aurora Kinase B Is Important for Biologic Activity of the Dual Inhibitors of BCR-ABL and Aurora Kinases R763/AS703569 and PHA-739358 in BCR-ABL Transformed Cells

    PubMed Central

    Illert, Anna L.; Seitz, Anna K.; Rummelt, Christoph; Kreutmair, Stefanie; Engh, Richard A.; Goodstal, Samantha; Peschel, Christian; Duyster, Justus; von Bubnoff, Nikolas

    2014-01-01

    ABL tyrosine kinase inhibitors (TKI) like Imatinib, Dasatinib and Nilotinib are the gold standard in conventional treatment of CML. However, the emergence of resistance remains a major problem. Alternative therapeutic strategies of ABL TKI-resistant CML are urgently needed. We asked whether dual inhibition of BCR-ABL and Aurora kinases A-C could overcome resistance mediated by ABL kinase mutations. We therefore tested the dual ABL and Aurora kinase inhibitors PHA-739358 and R763/AS703569 in Ba/F3- cells ectopically expressing wild type (wt) or TKI-resistant BCR-ABL mutants. We show that both compounds exhibited strong anti-proliferative and pro-apoptotic activity in ABL TKI resistant cell lines including cells expressing the strongly resistant T315I mutation. Cell cycle analysis indicated polyploidisation, a consequence of continued cell cycle progression in the absence of cell division by Aurora kinase inhibition. Experiments using drug resistant variants of Aurora B indicated that PHA-739358 acts on both, BCR-ABL and Aurora Kinase B, whereas Aurora kinase B inhibition might be sufficient for the anti-proliferative activity observed with R763/AS703569. Taken together, our data demonstrate that dual ABL and Aurora kinase inhibition might be used to overcome ABL TKI resistant CML. PMID:25426931

  18. 9-(Arenethenyl)purines as dual Src/Abl kinase inhibitors targeting the inactive conformation: design, synthesis, and biological evaluation.

    PubMed

    Huang, Wei-Sheng; Zhu, Xiaotian; Wang, Yihan; Azam, Mohammad; Wen, David; Sundaramoorthi, Raji; Thomas, R Mathew; Liu, Shuangying; Banda, Geetha; Lentini, Scott P; Das, Sasmita; Xu, Qihong; Keats, Jeff; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Marc I; Russian, Karin; Daley, George Q; Iuliucci, John; Dalgarno, David C; Clackson, Tim; Sawyer, Tomi K; Shakespeare, William C

    2009-08-13

    A novel series of potent dual Src/Abl kinase inhibitors based on a 9-(arenethenyl)purine core has been identified. Unlike traditional dual Src/Abl inhibitors targeting the active enzyme conformation, these inhibitors bind to the inactive, DFG-out conformation of both kinases. Extensive SAR studies led to the discovery of potent and orally bioavailable inhibitors, some of which demonstrated in vivo efficacy. Once-daily oral administration of inhibitor 9i (AP24226) significantly prolonged the survival of mice injected intravenously with wild type Bcr-Abl expressing Ba/F3 cells at a dose of 10 mg/kg. In a separate model, oral administration of 9i to mice bearing subcutaneous xenografts of Src Y527F expressing NIH 3T3 cells elicited dose-dependent tumor shrinkage with complete tumor regression observed at the highest dose. Notably, several inhibitors (e.g., 14a, AP24163) exhibited modest cellular potency (IC50 = 300-400 nM) against the Bcr-Abl mutant T315I, a variant resistant to all currently marketed therapies for chronic myeloid leukemia.

  19. Binding free energy calculation with QM/MM hybrid methods for Abl-Kinase inhibitor.

    PubMed

    Dubey, Kshatresh Dutta; Ojha, Rajendra Prasad

    2011-01-01

    We report a Quantum mechanics/Molecular Mechanics-Poisson-Boltzmann/ Surface Area (QM/MM-PB/SA) method to calculate the binding free energy of c-Abl human tyrosine kinase by combining the QM and MM principles where the ligand is treated quantum mechanically and the rest of the receptor by classical molecular mechanics. To study the role of entropy and the flexibility of the protein ligand complex in a solvated environment, molecular dynamics calculations are performed using a hybrid QM/MM approach. This work shows that the results of the QM/MM approach are strongly correlated with the binding affinity. The QM/MM interaction energy in our reported study confirms the importance of electronic and polarization contributions, which are often neglected in classical MM-PB/SA calculations. Moreover, a comparison of semi-empirical methods like DFTB-SCC, PM3, MNDO, MNDO-PDDG, and PDDG-PM3 is also performed. The results of the study show that the implementation of a DFTB-SCC semi-empirical Hamiltonian that is derived from DFT gives better results than other methods. We have performed such studies using the AMBER molecular dynamic package for the first time. The calculated binding free energy is also in agreement with the experimentally determined binding affinity for c-Abl tyrosine kinase complex with Imatinib.Electronic supplementary material The online version of this article (doi:10.1007/s10867-010-9199-z) contains supplementary material, which is available to authorized users.

  20. Conformational control inhibition of the BCR-ABL1 tyrosine kinase, including the gatekeeper T315I mutant, by the switch-control inhibitor DCC-2036

    PubMed Central

    Chan, Wayne W.; Wise, Scott C.; Kaufman, Michael D.; Ahn, Yu Mi; Ensinger, Carol L.; Haack, Torsten; Hood, Molly M.; Jones, Jennifer; Lord, John W.; Lu, Wei Ping; Miller, David; Patt, William C.; Smith, Bryan D.; Petillo, Peter A.; Rutkoski, Thomas J.; Telikepalli, Hanumaiah; Vogeti, Lakshminarayana; Yao, Tony; Chun, Lawrence; Clark, Robin; Evangelista, Peter; Gavrilescu, L. Cristina; Lazarides, Katherine; Zaleskas, Virginia M.; Stewart, Lance J.; Van Etten, Richard A.; Flynn, Daniel L.

    2011-01-01

    Summary Acquired resistance to ABL1 tyrosine kinase inhibitors (TKIs) through ABL1 kinase domain mutations, particularly the gatekeeper mutant T315I, is a significant problem for chronic myeloid leukemia (CML) patients. Using structure-based drug design, we developed compounds that bind to residues (Arg386/Glu282) ABL1 uses to switch between inactive and active conformations. The lead “switch-control” inhibitor, DCC-2036, potently inhibits both unphosphorylated and phosphorylated ABL1 by inducing a type II inactive conformation, and retains efficacy against the majority of clinically relevant CML resistance mutants, including T315I. DCC-2036 inhibits BCR-ABL1T315I-expressing cell lines, prolongs survival in mouse models of T315I-mutant CML and B-lymphoblastic leukemia, and inhibits primary patient leukemia cells expressing T315I in vitro and in vivo, supporting its clinical development in TKI-resistant Ph+ leukemia. PMID:21481795

  1. 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

    PubMed Central

    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

  2. Transposon-mediated generation of BCR-ABL1-expressing transgenic cell lines for unbiased sensitivity testing of tyrosine kinase inhibitors

    PubMed Central

    Berkowitsch, Bettina; Koenig, Margit; Haas, Oskar A.; Hoermann, Gregor; Valent, Peter; Lion, Thomas

    2016-01-01

    Point mutations in the ABL1 kinase domain are an important mechanism of resistance to tyrosine kinase inhibitors (TKI) in BCR-ABL1-positive and, as recently shown, BCR-ABL1-like leukemias. The cell line Ba/F3 lentivirally transduced with mutant BCR-ABL1 constructs is widely used for in vitro sensitivity testing and response prediction to tyrosine kinase inhibitors. The transposon-based Sleeping Beauty system presented offers several advantages over lentiviral transduction including the absence of biosafety issues, faster generation of transgenic cell lines, and greater efficacy in introducing large gene constructs. Nevertheless, both methods can mediate multiple insertions in the genome. Here we show that multiple BCR-ABL1 insertions result in elevated IC50 levels for individual TKIs, thus overestimating the actual resistance of mutant subclones. We have therefore established flow-sorting-based fractionation of BCR-ABL1-transformed Ba/F3 cells facilitating efficient enrichment of cells carrying single-site insertions, as demonstrated by FISH-analysis. Fractions of unselected Ba/F3 cells not only showed a greater number of BCR-ABL1 hybridization signals, but also revealed higher IC50 values for the TKIs tested. The data presented highlight the need to carefully select transfected cells by flow-sorting, and to control the insertion numbers by FISH and real-time PCR to permit unbiased in vitro testing of drug resistance. PMID:27801667

  3. BCR-ABL mutations in chronic myeloid leukemia treated with tyrosine kinase inhibitors and impact on survival.

    PubMed

    Pagnano, Katia Borgia Barbosa; Bendit, Israel; Boquimpani, Carla; De Souza, Carmino Antonio; Miranda, Eliana C M; Zalcberg, Ilana; Larripa, Irene; Nardinelli, Luciana; Silveira, Rosana Antunes; Fogliatto, Laura; Spector, Nelson; Funke, Vaneuza; Pasquini, Ricardo; Hungria, Vania; Chiattone, Carlos Sérgio; Clementino, Nelma; Conchon, Monika; Moiraghi, Elena Beatriz; Lopez, Jose Luis; Pavlovsky, Carolina; Pavlovsky, Miguel A; Cervera, Eduardo E; Meillon, Luis Antonio; Simões, Belinda; Hamerschlak, Nelson; Bozzano, Alicia Helena Magarinos; Mayta, Ernesto; Cortes, Jorge; Bengió, Raquel M

    2015-01-01

    This is the largest Latin American study of BCR-ABL mutations in chronic myeloid leukemia (CML) patients, resistant to imatinib (IM). In 195/467 (41%) patients, mutations were detected. The most frequent mutation was T315I (n = 31, 16%). Progression-free (PFS) and overall survival (OS) at 5 years were lower in patients with BCR-ABL mutations (43% vs. 65%, p = 0.07 and 47% vs. 72%, p = 0.03, respectively) and in those with the T315I mutation (p = 0.003 and p = 0.03). OS and PFS were superior in subgroup who switched to second generation inhibitors (SGIs) after IM failure (OS: 50% vs. 39% p = 0.01; PFS: 48% vs. 30% p = 0.02). BCR-ABL mutations conferred a significant poor prognosis in CML patients.

  4. BCR-ABL tyrosine kinase inhibitor pharmacophore model derived from a series of phenylaminopyrimidine-based (PAP) derivatives.

    PubMed

    Cui, Jing; Fu, Rao; Zhou, Li-Hua; Chen, Sheng-Ping; Li, Guang-Wu; Qian, Shen-Xian; Liu, Shu

    2013-04-15

    To reveal novel insights into the inhibition of BCR-ABL tyrosine kinase, pharmacophore mapping studies were performed for a series of phenylaminopyrimidine-based (PAP) derivatives, including imatinib (Gleevec). A seven-point pharmacophore model with one hydrophobic group (H), two hydrogen bond donors (D) and four aromatic rings (R) was developed using phase (pharmacophore alignment & scoring engine). The pharmacophore hypothesis yielded a statistically significant 3D-QSAR model, with a correlation coefficient of 0.886 and a survival score of 4.97 for training set molecules. The model showed excellent predictive power, with a correlation coefficient of Q(2)=0.768 for an external test set of ten molecules. The results obtained from our studies provide a valuable tool for designing new lead molecules with potent activity.

  5. Efficacy and safety of radotinib in chronic phase chronic myeloid leukemia patients with resistance or intolerance to BCR-ABL1 tyrosine kinase inhibitors.

    PubMed

    Kim, Sung-Hyun; Menon, Hari; Jootar, Saengsuree; Saikia, Tapan; Kwak, Jae-Yong; Sohn, Sang-Kyun; Park, Joon Seong; Jeong, Seong Hyun; Kim, Hyeoung Joon; Kim, Yeo-Kyeoung; Oh, Suk Joong; Kim, Hawk; Zang, Dae Young; Chung, Joo Seop; Shin, Ho Jin; Do, Young Rok; Kim, Jeong-A; Kim, Dae-Young; Choi, Chul Won; Park, Sahee; Park, Hye Lin; Lee, Gong Yeal; Cho, Dae Jin; Shin, Jae Soo; Kim, Dong-Wook

    2014-07-01

    Radotinib (IY5511HCL), a novel and selective BCR-ABL1 tyrosine kinase inhibitor, has shown pre-clinical and phase I activity and safety in chronic myeloid leukemia. This phase II study investigated the efficacy and safety of radotinib in Philadelphia chromosome-positive chronic phase-chronic myeloid leukemia patients with resistance and/or intolerance to BCR-ABL1 tyrosine kinase inhibitors. Patients received radotinib 400 mg twice daily for 12 cycles based on results from the phase I trial. The primary end point was rate of major cytogenetic response by 12 months. A total of 77 patients were enrolled. Major cytogenetic response was achieved in 50 (65%; cumulative 75%) patients, including 36 (47%) patients with complete cytogenetic response by 12 months. Median time to major cytogenetic response and complete cytogenetic response were 85 days and 256 days, respectively. Major cytogenetic response and complete cytogenetic response rates were similar between imatinib-resistant and imatinib-intolerant patients, but were higher in patients without BCR-ABL1 mutations. Overall and progression-free survival rates at 12 months were 96.1% and 86.3%, respectively. All newly-occurring or worsening grade 3/4 hematologic abnormalities included thrombocytopenia (24.7%) and anemia (5.2%); grade 3/4 drug-related non-hematologic adverse events included fatigue (3.9%), asthenia (3.9%), and nausea (2.6%). The most common biochemistry abnormality was hyperbilirubinemia (grade 3/4 23.4%), and 12 of 18 cases were managed with dose modification. Study findings suggest radotinib is effective and well tolerated in chronic phase-chronic myeloid leukemia patients with resistance and/or intolerance to BCR-ABL1 tyrosine kinase inhibitors and may represent a promising alternative for these patients. (clinicaltrials.gov identifier: 01602952).

  6. Structure, Regulation, Signaling, and Targeting of Abl Kinases in Cancer

    PubMed Central

    2012-01-01

    Abl kinases are prototypic cytoplasmic tyrosine kinases and are involved in a variety of chromosomal aberrations in different cancers. This causes the expression of Abl fusion proteins, such as Bcr-Abl, that are constitutively activated and drivers of tumorigenesis. Over the past decades, biochemical and functional studies on the molecular mechanisms of Abl regulation have gone hand in hand with progression of our structural understanding of autoinhibited and active Abl conformations. In parallel, Abl oncoproteins have become prime molecular targets for cancer therapy, using adenosine triphosphate (ATP)–competitive kinase inhibitors, such as imatinib. Abl-targeting drugs serve as a paradigm for our understanding of kinase inhibitor action, specificity, and resistance development. In this review article, I will review the molecular mechanisms that are responsible for the regulation of Abl kinase activity and how oncogenic Abl fusions signal. Furthermore, past and ongoing efforts to target Abl oncoproteins using ATP-competitive and allosteric inhibitors, as well as future possibilities using combination therapy, will be discussed. PMID:23226581

  7. The HDAC inhibitor SB939 overcomes resistance to BCR-ABL kinase Inhibitors conferred by the BIM deletion polymorphism in chronic myeloid leukemia.

    PubMed

    Rauzan, Muhammad; Chuah, Charles T H; Ko, Tun Kiat; Ong, S Tiong

    2017-01-01

    Chronic myeloid leukemia (CML) treatment has been improved by tyrosine kinase inhibitors (TKIs) such as imatinib mesylate (IM) but various factors can cause TKI resistance in patients with CML. One factor which contributes to TKI resistance is a germline intronic deletion polymorphism in the BCL2-like 11 (BIM) gene which impairs the expression of pro-apoptotic splice isoforms of BIM. SB939 (pracinostat) is a hydroxamic acid based HDAC inhibitor with favorable pharmacokinetic, physicochemical and pharmaceutical properties, and we investigated if this drug could overcome BIM deletion polymorphism-induced TKI resistance. We found that SB939 corrects BIM pre-mRNA splicing in CML cells with the BIM deletion polymorphism, and induces apoptotic cell death in CML cell lines and primary cells with the BIM deletion polymorphism. More importantly, SB939 both decreases the viability of CML cell lines and primary CML progenitors with the BIM deletion and restores TKI-sensitivity. Our results demonstrate that SB939 overcomes BIM deletion polymorphism-induced TKI resistance, and suggest that SB939 may be useful in treating CML patients with BIM deletion-associated TKI resistance.

  8. The HDAC inhibitor SB939 overcomes resistance to BCR-ABL kinase Inhibitors conferred by the BIM deletion polymorphism in chronic myeloid leukemia

    PubMed Central

    Rauzan, Muhammad; Chuah, Charles T. H.; Ko, Tun Kiat; Ong, S. Tiong

    2017-01-01

    Chronic myeloid leukemia (CML) treatment has been improved by tyrosine kinase inhibitors (TKIs) such as imatinib mesylate (IM) but various factors can cause TKI resistance in patients with CML. One factor which contributes to TKI resistance is a germline intronic deletion polymorphism in the BCL2-like 11 (BIM) gene which impairs the expression of pro-apoptotic splice isoforms of BIM. SB939 (pracinostat) is a hydroxamic acid based HDAC inhibitor with favorable pharmacokinetic, physicochemical and pharmaceutical properties, and we investigated if this drug could overcome BIM deletion polymorphism-induced TKI resistance. We found that SB939 corrects BIM pre-mRNA splicing in CML cells with the BIM deletion polymorphism, and induces apoptotic cell death in CML cell lines and primary cells with the BIM deletion polymorphism. More importantly, SB939 both decreases the viability of CML cell lines and primary CML progenitors with the BIM deletion and restores TKI-sensitivity. Our results demonstrate that SB939 overcomes BIM deletion polymorphism-induced TKI resistance, and suggest that SB939 may be useful in treating CML patients with BIM deletion-associated TKI resistance. PMID:28301600

  9. Early BCR-ABL1 Transcript Decline after 1 Month of Tyrosine Kinase Inhibitor Therapy as an Indicator for Treatment Response in Chronic Myeloid Leukemia.

    PubMed

    El Missiry, Mohamed; Hjorth-Hansen, Henrik; Richter, Johan; Olson-Strömberg, Ulla; Stenke, Leif; Porkka, Kimmo; Kreutzman, Anna; Mustjoki, Satu

    2017-01-01

    In chronic myeloid leukemia (CML), early treatment prediction is important to identify patients with inferior overall outcomes. We examined the feasibility of using reductions in BCR-ABL1 transcript levels after 1 month of tyrosine kinase inhibitor (TKI) treatment to predict therapy response. Fifty-two first-line TKI-treated CML patients were included (imatinib n = 26, dasatinib n = 21, nilotinib n = 5), and BCR-ABL1 transcript levels were measured at diagnosis (dg) and 1, 3, 6, 12, 18, 24, and 36 months. The fold change of the BCR-ABL1 transcripts at 1 month compared to initial BCR-ABL1 transcript levels was used to indicate early therapy response. In our cohort, 21% of patients had no decrease in BCR-ABL1 transcript levels after 1 month and were classified as poor responders. Surprisingly, these patients had lower BCR-ABL1 transcript levels at dg compared to responders (31% vs. 48%, p = 0.0083). Poor responders also significantly more often had enlarged spleen (55% vs. 15%; p<0.01) and a higher percentage of Ph+ CD34+CD38- cells in the bone marrow (91% vs. 75%, p<0.05). The major molecular response rates were inferior in the poor responders (at 12m 18% vs. 64%, p<0.01; 18m 27% vs. 75%, p<0.01; 24m 55% vs. 87%, p<0.01). In conclusion, early treatment response analysis defines a biologically distinct patient subgroup with inferior long-term outcomes.

  10. Early BCR-ABL1 Transcript Decline after 1 Month of Tyrosine Kinase Inhibitor Therapy as an Indicator for Treatment Response in Chronic Myeloid Leukemia

    PubMed Central

    Hjorth-Hansen, Henrik; Richter, Johan; Olson-Strömberg, Ulla; Stenke, Leif; Porkka, Kimmo; Kreutzman, Anna; Mustjoki, Satu

    2017-01-01

    In chronic myeloid leukemia (CML), early treatment prediction is important to identify patients with inferior overall outcomes. We examined the feasibility of using reductions in BCR-ABL1 transcript levels after 1 month of tyrosine kinase inhibitor (TKI) treatment to predict therapy response. Fifty-two first-line TKI-treated CML patients were included (imatinib n = 26, dasatinib n = 21, nilotinib n = 5), and BCR-ABL1 transcript levels were measured at diagnosis (dg) and 1, 3, 6, 12, 18, 24, and 36 months. The fold change of the BCR-ABL1 transcripts at 1 month compared to initial BCR-ABL1 transcript levels was used to indicate early therapy response. In our cohort, 21% of patients had no decrease in BCR-ABL1 transcript levels after 1 month and were classified as poor responders. Surprisingly, these patients had lower BCR-ABL1 transcript levels at dg compared to responders (31% vs. 48%, p = 0.0083). Poor responders also significantly more often had enlarged spleen (55% vs. 15%; p<0.01) and a higher percentage of Ph+ CD34+CD38- cells in the bone marrow (91% vs. 75%, p<0.05). The major molecular response rates were inferior in the poor responders (at 12m 18% vs. 64%, p<0.01; 18m 27% vs. 75%, p<0.01; 24m 55% vs. 87%, p<0.01). In conclusion, early treatment response analysis defines a biologically distinct patient subgroup with inferior long-term outcomes. PMID:28135325

  11. Patan hospital experience in treating philadelphia chromosome/BCR-ABL1 positive chronic myeloid leukemia patients with gleevec (imatinib mesylate); the first generation specific tyrosine kinase inhibitor

    PubMed Central

    2010-01-01

    Background Chronic Myeloid Leukemia (CML) is caused by the abnormal fusion protein BCR-ABL1, a constitutively active tyrosine kinase and product of the Philadelphia chromosome. Gleevec (Imatinib mesylate) is a selective inhibitor of this kinase. Treatment with this agent is known to result in hematologic, cytogenetic, and molecular responses. Patan hospital (Patan, Nepal) is one of the Gleevec International Patient Assistance Program (GIPAP) centers for patients with CML. Methods A total of 106 Philadelphia positive CML patients were enrolled in our center between Feb 2003 and Jun 2008, and 103 of them were eligible for cytogenetic and/or hematologic response analyses. Results Out of 103 patients, 27% patients underwent cytogenetic analysis. Imatinib induced major cytogenetic responses in 89% and complete hematologic responses in almost 100% of the patients with confirmed CML. After a mean follow up of 27 months, an estimated 90% of the patients on imatinib remained in hematologic remission and more than 90% of the patients are still alive. About 30% of patients developed some form of manageable myelosuppression. A few patients developed non-hematologic toxic side effects such as edema and hepatotoxicity. Conclusions Our study demonstrates that imatinib is safe to use in a developing country. Furthermore, we demonstrate that imatinib is very effective and induced long lasting responses in a high proportion of patients with Ph chromosome/BCR-ABL1 positive CML. Imatinib is well tolerated by our patients. The lack of cytogenetic analysis in the majority of our patients hindered our ability to detect inadequate responses to imatinib and adjust therapy appropriately. PMID:21138592

  12. Switching to second-generation tyrosine kinase inhibitor improves the response and outcome of frontline imatinib-treated patients with chronic myeloid leukemia with more than 10% of BCR-ABL/ABL ratio at 3 months

    PubMed Central

    Casado, Luis-Felipe; García-Gutiérrez, José-Valentín; Massagué, Isabel; Giraldo, Pilar; Pérez-Encinas, Manuel; de Paz, Raquel; Martínez-López, Joaquín; Bautista, Guiomar; Osorio, Santiago; Requena, María-José; Palomera, Luis; Peñarrubia, María-Jesús; Calle, Carmen; Hernández-Rivas, José-Ángel; Burgaleta, Carmen; Maestro, Begoña; García-Ormeña, Nuria; Steegmann, Juan-Luis

    2015-01-01

    Chronic myeloid leukemia patients display heterogeneous responses to imatinib. Survival depends on baseline clinical characteristics (including prognostic scoring systems) and on early response (such as >10% BCR-ABL/ABL ratio at 3 months of therapy). The results of switching to second-generation tyrosine kinase inhibitors (2GTKIs) may contain a bias since, in the majority of these studies, patients who switch treatment due to intolerance or failure are censored or excluded. We analyzed the Spanish Registry data on switching in an intention-to-treat analysis of patients in standard clinical practice. Switching to 2GTKIs improves responses from 45% to 75% of complete cytogenetic response (CCyR) and from 15% to 45% of major molecular response (MMR) in the group without molecular response 1 (MR1) at 3 months and from 70% to 87% in CCyR and from 52% to 87% in MMR in the group with MR1. The final response rate is poorer in the group with no MR1 at 3 months. Nevertheless, the differences in the rates of response were not translated into differences in major events (transformations or deaths), and the final progression-free survival and overall survival were similar. PMID:25756742

  13. Switching to second-generation tyrosine kinase inhibitor improves the response and outcome of frontline imatinib-treated patients with chronic myeloid leukemia with more than 10% of BCR-ABL/ABL ratio at 3 months.

    PubMed

    Casado, Luis-Felipe; García-Gutiérrez, José-Valentín; Massagué, Isabel; Giraldo, Pilar; Pérez-Encinas, Manuel; de Paz, Raquel; Martínez-López, Joaquín; Bautista, Guiomar; Osorio, Santiago; Requena, María-José; Palomera, Luis; Peñarrubia, María-Jesús; Calle, Carmen; Hernández-Rivas, José-Ángel; Burgaleta, Carmen; Maestro, Begoña; García-Ormeña, Nuria; Steegmann, Juan-Luis

    2015-07-01

    Chronic myeloid leukemia patients display heterogeneous responses to imatinib. Survival depends on baseline clinical characteristics (including prognostic scoring systems) and on early response (such as >10% BCR-ABL/ABL ratio at 3 months of therapy). The results of switching to second-generation tyrosine kinase inhibitors (2GTKIs) may contain a bias since, in the majority of these studies, patients who switch treatment due to intolerance or failure are censored or excluded. We analyzed the Spanish Registry data on switching in an intention-to-treat analysis of patients in standard clinical practice. Switching to 2GTKIs improves responses from 45% to 75% of complete cytogenetic response (CCyR) and from 15% to 45% of major molecular response (MMR) in the group without molecular response 1 (MR1) at 3 months and from 70% to 87% in CCyR and from 52% to 87% in MMR in the group with MR1. The final response rate is poorer in the group with no MR1 at 3 months. Nevertheless, the differences in the rates of response were not translated into differences in major events (transformations or deaths), and the final progression-free survival and overall survival were similar.

  14. Pharmacophore modeling of nilotinib as an inhibitor of ATP-binding cassette drug transporters and BCR-ABL kinase using a three-dimensional quantitative structure-activity relationship approach.

    PubMed

    Shukla, Suneet; Kouanda, Abdul; Silverton, Latoya; Talele, Tanaji T; Ambudkar, Suresh V

    2014-07-07

    Nilotinib (Tasigna) is a tyrosine kinase inhibitor approved by the FDA to treat chronic phase chronic myeloid leukemia patients. It is also a transport substrate of the ATP-binding cassette (ABC) drug efflux transporters ABCB1 (P-glycoprotein, P-gp) and ABCG2 (BCRP), which may have an effect on the pharmacokinetics and toxicity of this drug. The goal of this study was to identify pharmacophoric features of nilotinib in order to potentially develop specific inhibitors of BCR-ABL kinase with minimal interactions with ABC drug transporters. Three-dimensional pharmacophore modeling and quantitative structure-activity relationship (QSAR) studies were carried out on a series of nilotinib analogues to identify chemical features that contribute to inhibitory activity of nilotinib against BCR-ABL kinase activity, P-gp, and ABCG2. Twenty-five derivatives of nilotinib were synthesized and were then tested to measure their activity to inhibit BCR-ABL kinase and to inhibit the function of ABC drug transporters. A set of in vitro experiments including kinase activity and cell-based transport assays and photolabeling of P-gp and ABCG2 with a transport substrate, [(125)I]-iodoarylazido-prazosin (IAAP), were carried out in isolated membranes to evaluate the potency of the derivatives to inhibit the function of ABC drug transporters and BCR-ABL kinase. Sixteen, fourteen, and ten compounds were selected as QSAR data sets, respectively, to generate PHASE v3.1 pharmacophore models for BCR-ABL kinase, ABCG2, and P-gp inhibitors. The IC50 values of these derivatives against P-gp, ABCG2, or BCR-ABL kinase were used to generate pharmacophore features required for optimal interactions with these targets. A seven-point pharmacophore (AADDRRR) for BCR-ABL kinase inhibitory activity, a six-point pharmacophore (ADHRRR) for ABCG2 inhibitory activity, and a seven-point pharmacophore (AADDRRR) for P-gp inhibitory activity were generated. The derived models clearly demonstrate high predictive power

  15. Pharmacophore Modeling of Nilotinib as an Inhibitor of ATP-Binding Cassette Drug Transporters and BCR-ABL Kinase Using a Three-Dimensional Quantitative Structure–Activity Relationship Approach

    PubMed Central

    2015-01-01

    Nilotinib (Tasigna) is a tyrosine kinase inhibitor approved by the FDA to treat chronic phase chronic myeloid leukemia patients. It is also a transport substrate of the ATP-binding cassette (ABC) drug efflux transporters ABCB1 (P-glycoprotein, P-gp) and ABCG2 (BCRP), which may have an effect on the pharmacokinetics and toxicity of this drug. The goal of this study was to identify pharmacophoric features of nilotinib in order to potentially develop specific inhibitors of BCR-ABL kinase with minimal interactions with ABC drug transporters. Three-dimensional pharmacophore modeling and quantitative structure–activity relationship (QSAR) studies were carried out on a series of nilotinib analogues to identify chemical features that contribute to inhibitory activity of nilotinib against BCR-ABL kinase activity, P-gp, and ABCG2. Twenty-five derivatives of nilotinib were synthesized and were then tested to measure their activity to inhibit BCR-ABL kinase and to inhibit the function of ABC drug transporters. A set of in vitro experiments including kinase activity and cell-based transport assays and photolabeling of P-gp and ABCG2 with a transport substrate, [125I]-iodoarylazido-prazosin (IAAP), were carried out in isolated membranes to evaluate the potency of the derivatives to inhibit the function of ABC drug transporters and BCR-ABL kinase. Sixteen, fourteen, and ten compounds were selected as QSAR data sets, respectively, to generate PHASE v3.1 pharmacophore models for BCR-ABL kinase, ABCG2, and P-gp inhibitors. The IC50 values of these derivatives against P-gp, ABCG2, or BCR-ABL kinase were used to generate pharmacophore features required for optimal interactions with these targets. A seven-point pharmacophore (AADDRRR) for BCR-ABL kinase inhibitory activity, a six-point pharmacophore (ADHRRR) for ABCG2 inhibitory activity, and a seven-point pharmacophore (AADDRRR) for P-gp inhibitory activity were generated. The derived models clearly demonstrate high predictive power

  16. Identification of novel tyrosine kinase inhibitors for drug resistant T315I mutant BCR-ABL: a virtual screening and molecular dynamics simulations study

    PubMed Central

    Banavath, Hemanth Naick; Sharma, Om Prakash; Kumar, Muthuvel Suresh; Baskaran, R.

    2014-01-01

    BCR-ABL tyrosine kinase plays a major role in the pathogenesis of chronic myeloid leukemia (CML) and is a proven target for drug development. Currently available drugs in the market are effective against CML; however, side-effects and drug-resistant mutations in BCR-ABL limit their full potential. Using high throughput virtual screening approach, we have screened several small molecule databases and docked against wild-type and drug resistant T315I mutant BCR-ABL. Drugs that are currently available, such as imatinib and ponatinib, were also docked against BCR-ABL protein to set a cutoff value for our screening. Selected lead compounds were further evaluated for chemical reactivity employing density functional theory approach, all selected ligands shows HLG value > 0.09900 and the binding free energy between protein-ligand complex interactions obtained was rescored using MM-GBSA. The selected compounds showed least ΔG score −71.53 KJ/mol to maximum −126.71 KJ/mol in both wild type and drug resistant T315I mutant BCR-ABL. Following which, the stability of the docking complexes were evaluated by molecular dynamics simulation (MD) using GROMACS4.5.5. Results uncovered seven lead molecules, designated with Drug-Bank and PubChem ids as DB07107, DB06977, ST013616, DB04200, ST007180 ST019342, and DB01172, which shows docking scores higher than imatinib and ponatinib. PMID:25382104

  17. Identification of novel tyrosine kinase inhibitors for drug resistant T315I mutant BCR-ABL: a virtual screening and molecular dynamics simulations study

    NASA Astrophysics Data System (ADS)

    Banavath, Hemanth Naick; Sharma, Om Prakash; Kumar, Muthuvel Suresh; Baskaran, R.

    2014-11-01

    BCR-ABL tyrosine kinase plays a major role in the pathogenesis of chronic myeloid leukemia (CML) and is a proven target for drug development. Currently available drugs in the market are effective against CML; however, side-effects and drug-resistant mutations in BCR-ABL limit their full potential. Using high throughput virtual screening approach, we have screened several small molecule databases and docked against wild-type and drug resistant T315I mutant BCR-ABL. Drugs that are currently available, such as imatinib and ponatinib, were also docked against BCR-ABL protein to set a cutoff value for our screening. Selected lead compounds were further evaluated for chemical reactivity employing density functional theory approach, all selected ligands shows HLG value > 0.09900 and the binding free energy between protein-ligand complex interactions obtained was rescored using MM-GBSA. The selected compounds showed least ΔG score -71.53 KJ/mol to maximum -126.71 KJ/mol in both wild type and drug resistant T315I mutant BCR-ABL. Following which, the stability of the docking complexes were evaluated by molecular dynamics simulation (MD) using GROMACS4.5.5. Results uncovered seven lead molecules, designated with Drug-Bank and PubChem ids as DB07107, DB06977, ST013616, DB04200, ST007180 ST019342, and DB01172, which shows docking scores higher than imatinib and ponatinib.

  18. [Kinase inhibitors against hematological malignancies].

    PubMed

    Tojo, Arinobu

    2014-06-01

    Dysregulation of protein phosphorylation, especially on tyrosine residues, plays a crucial role in development and progression of hematological malignancies. Since remarkable success in imatinib therapy of CML and Ph+ALL, extensive efforts have made to explore candidate molecular targets and next breakthrough drugs. Now that next generation ABL kinase inhibitors are available for CML, the therapeutic algorithm has been revolutionized. As for AML and lymphoid malignancies, many kinase inhibitors targeting FLT3, BTK and aurora-A are on early and late clinical trials, and a number of promising drugs including ibrutinib are picked up for further evaluation.

  19. Abl family kinases regulate FcγR-mediated phagocytosis in murine macrophages.

    PubMed

    Greuber, Emileigh K; Pendergast, Ann Marie

    2012-12-01

    Phagocytosis of Ab-coated pathogens is mediated through FcγRs, which activate intracellular signaling pathways to drive actin cytoskeletal rearrangements. Abl and Arg define a family of nonreceptor tyrosine kinases that regulate actin-dependent processes in a variety of cell types, including those important in the adaptive immune response. Using pharmacological inhibition as well as dominant negative and knockout approaches, we demonstrate a role for the Abl family kinases in phagocytosis by macrophages and define a mechanism whereby Abl kinases regulate this process. Bone marrow-derived macrophages from mice lacking Abl and Arg kinases exhibit inefficient phagocytosis of sheep erythrocytes and zymosan particles. Treatment with the Abl kinase inhibitors imatinib and GNF-2 or overexpression of kinase-inactive forms of the Abl family kinases also impairs particle internalization in murine macrophages, indicating Abl kinase activity is required for efficient phagocytosis. Further, Arg kinase is present at the phagocytic cup, and Abl family kinases are activated by FcγR engagement. The regulation of phagocytosis by Abl family kinases is mediated in part by the spleen tyrosine kinase (Syk). Loss of Abl and Arg expression or treatment with Abl inhibitors reduced Syk phosphorylation in response to FcγR ligation. The link between Abl family kinases and Syk may be direct, as purified Arg kinase phosphorylates Syk in vitro. Further, overexpression of membrane-targeted Syk in cells treated with Abl kinase inhibitors partially rescues the impairment in phagocytosis. Together, these findings reveal that Abl family kinases control the efficiency of phagocytosis in part through the regulation of Syk function.

  20. The SH2 domain of Abl kinases regulates kinase autophosphorylation by controlling activation loop accessibility

    NASA Astrophysics Data System (ADS)

    Lamontanara, Allan Joaquim; Georgeon, Sandrine; Tria, Giancarlo; Svergun, Dmitri I.; Hantschel, Oliver

    2014-11-01

    The activity of protein kinases is regulated by multiple molecular mechanisms, and their disruption is a common driver of oncogenesis. A central and almost universal control element of protein kinase activity is the activation loop that utilizes both conformation and phosphorylation status to determine substrate access. In this study, we use recombinant Abl tyrosine kinases and conformation-specific kinase inhibitors to quantitatively analyse structural changes that occur after Abl activation. Allosteric SH2-kinase domain interactions were previously shown to be essential for the leukemogenesis caused by the Bcr-Abl oncoprotein. We find that these allosteric interactions switch the Abl activation loop from a closed to a fully open conformation. This enables the trans-autophosphorylation of the activation loop and requires prior phosphorylation of the SH2-kinase linker. Disruption of the SH2-kinase interaction abolishes activation loop phosphorylation. Our analysis provides a molecular mechanism for the SH2 domain-dependent activation of Abl that may also regulate other tyrosine kinases.

  1. [Tyrosine kinase inhibitors].

    PubMed

    Robert, Jacques

    2011-11-01

    Membrane receptors with tyrosine kinase activity and cytoplasmic tyrosine kinases have emerged as important potential targets in oncology. Starting from basic structures such as anilino-quinazoline, numerous compounds have been synthesised, with the help of tyrosine kinase crystallography, which has allowed to optimise protein-ligand interactions. The catalytic domains of all kinases present similar three-dimensional structures, which explains that it may be difficult to identify molecules having a high specificity for a given tyrosine kinase. Some tyrosine kinase inhibitors are relatively specific for epidermal growth factor receptor (EGFR) such as géfitinib and erlotinib; other are mainly active against platelet-derived growth factor receptor (PDGFR) and the receptor KIT, such as imatinib or nilotinib, and other against vascular endothelial growth factor (VEGF) receptors involved in angiogenesis, such as sunitinib and sorafenib. The oral formulation of tyrosine kinase inhibitors is well accepted by the patients but may generate sometimes compliance problems requiring pharmacokinetic monitoring. This chemical family is in full expansion and several dozens of compounds have entered clinical trials.

  2. Kinase Inhibitors from Marine Sponges

    PubMed Central

    Skropeta, Danielle; Pastro, Natalie; Zivanovic, Ana

    2011-01-01

    Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included. PMID:22073013

  3. Inactivation of ABL kinases suppresses non–small cell lung cancer metastasis

    PubMed Central

    Gu, Jing Jin; Rouse, Clay; Wang, Jun; Onaitis, Mark W.

    2016-01-01

    Current therapies to treat non–small cell lung carcinoma (NSCLC) have proven ineffective owing to transient, variable, and incomplete responses. Here we show that ABL kinases, ABL1 and ABL2, promote metastasis of lung cancer cells harboring EGFR or KRAS mutations. Inactivation of ABL kinases suppresses NSCLC metastasis to brain and bone, and other organs. ABL kinases are required for expression of prometastasis genes. Notably, ABL1 and ABL2 depletion impairs extravasation of lung adenocarcinoma cells into the lung parenchyma. We found that ABL-mediated activation of the TAZ and β-catenin transcriptional coactivators is required for NSCLC metastasis. ABL kinases activate TAZ and β-catenin by decreasing their interaction with the β-TrCP ubiquitin ligase, leading to increased protein stability. High-level expression of ABL1, ABL2, and a subset of ABL-dependent TAZ- and β-catenin–target genes correlates with shortened survival of lung adenocarcinoma patients. Thus, ABL-specific allosteric inhibitors might be effective to treat metastatic lung cancer with an activated ABL pathway signature. PMID:28018973

  4. Structure of the ABL2/ARG kinase in complex with dasatinib.

    PubMed

    Ha, Byung Hak; Simpson, Mark Adam; Koleske, Anthony J; Boggon, Titus J

    2015-04-01

    ABL2/ARG (ABL-related gene) belongs to the ABL (Abelson tyrosine-protein kinase) family of tyrosine kinases. ARG plays important roles in cell morphogenesis, motility, growth and survival, and many of these biological roles overlap with the cellular functions of the ABL kinase. Chronic myeloid leukemia (CML) is associated with constitutive ABL kinase activation resulting from fusion between parts of the breakpoint cluster region (BCR) and ABL1 genes. Similarly, fusion of the ETV6 (Tel) and ARG genes drives some forms of T-cell acute lymphoblastic leukemia (T-ALL) and acute myeloid leukemia (AML). Dasatinib is a tyrosine kinase inhibitor used for the treatment of CML by inhibiting ABL, and while it also inhibits ARG, there is currently no structure of ARG in complex with dasatinib. Here, the co-crystal structure of the mouse ARG catalytic domain with dasatinib at 2.5 Å resolution is reported. Dasatinib-bound ARG is found in the DFG-in conformation although it is nonphosphorylated on the activation-loop tyrosine. In this structure the glycine-rich P-loop is found in a relatively open conformation compared with other known ABL family-inhibitor complex structures.

  5. Targeting the SH2-Kinase Interface in Bcr-Abl Inhibits Leukemogenesis

    SciTech Connect

    Grebien, Florian; Hantschel, Oliver; Wojcik, John; Kaupe, Ines; Kovacic, Boris; Wyrzucki, Arkadiusz M.; Gish, Gerald D.; Cerny-Reiterer, Sabine; Koide, Akiko; Beug, Hartmut; Pawson, Tony; Valent, Peter; Koide, Shohei; Superti-Furga, Giulio

    2012-10-25

    Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of the SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention.

  6. Phosphorylation of Dok1 by Abl family kinases inhibits CrkI transforming activity

    PubMed Central

    Ng, Khong Y.; Yin, Taofei; Machida, Kazuya; Wu, Yi I.; Mayer, Bruce J.

    2014-01-01

    The Crk SH2/SH3 adaptor and the Abl nonreceptor tyrosine kinase were first identified as oncoproteins, and both can induce tumorigenesis when overexpressed or mutationally activated. We previously reported the surprising finding that inhibition or knockdown of Abl family kinases enhanced transformation of mouse fibroblasts by CrkI. Abl family inhibitors are currently used or are being tested for treatment of human malignancies, and our finding raised concerns that such inhibitors might actually promote the growth of tumors overexpressing CrkI. Here, we identify the Dok1 adaptor as the key effector for the enhancement of CrkI transformation by Abl inhibition. We show that phosphorylation of tyrosines 295 and 361 of Dok1 by Abl family kinases suppresses CrkI transforming activity, and that upon phosphorylation these tyrosines bind the SH2 domains of the Ras inhibitor p120 RasGAP. Knockdown of RasGAP resulted in a similar enhancement of CrkI transformation, consistent with a critical role for Ras activity. Imaging studies using a FRET sensor of Ras activation revealed alterations in the localization of activated Ras in CrkI-transformed cells. Our results support a model in which Dok1 phosphorylation normally suppresses localized Ras pathway activity in Crk-transformed cells via recruitment and/or activation of RasGAP, and that preventing this negative feedback mechanism by inhibiting Abl family kinases leads to enhanced transformation by Crk. PMID:25043303

  7. Benzimidazole derivatives as kinase inhibitors.

    PubMed

    Garuti, Laura; Roberti, Marinella; Bottegoni, Giovanni

    2014-01-01

    Benzimidazole is a common kinase inhibitor scaffold and benzimidazole-based compounds interact with enzymes by multiple binding modes. In some cases, the benzimidazole acts as part of the hinge-binding motif, in others it has a scaffolding role without evidence for direct hinge binding. Several of these compounds are ATP-competitive inhibitors and show high selectivity by exploiting unique structural properties that distinguish one kinase from the majority of other kinases. However, the high specificity for a single target is not always sufficient. Thus another approach, called multi-target therapy, has been developed over the last few years. The simultaneous inhibition of various kinases may be useful because the disease is attacked at several relevant targets. Moreover, if a kinase becomes drug-resistant, a multitargeted drug can act on the other kinases. Some benzimidazole derivatives are multi-target inhibitors. In this article benzimidazole inhibitors are reported with their mechanisms of action, structure-activity relationship (SAR) and biological properties.

  8. Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells.

    PubMed

    Yuan, Chun-Xiu; Zhou, Zhi-Wei; Yang, Yin-Xue; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Tianxing; Pan, Si-Yuan; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora kinases and a third-generation Bcr-Abl tyrosine kinase inhibitor with potent anticancer effects, but its antitumor effect and underlying mechanisms in the treatment of human gastric cancer are unknown. This study aimed to investigate the effects of danusertib on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition and the molecular mechanisms involved in human gastric cancer AGS and NCI-N78 cells. The results showed that danusertib had potent growth-inhibitory, apoptosis-inducing, and autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways as well as activation of 5' AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression of

  9. Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells

    PubMed Central

    Yuan, Chun-Xiu; Zhou, Zhi-Wei; Yang, Yin-Xue; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Tianxing; Pan, Si-Yuan; Chen, Xiao-Wu; Zhou, Shu-Feng

    2015-01-01

    Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora kinases and a third-generation Bcr-Abl tyrosine kinase inhibitor with potent anticancer effects, but its antitumor effect and underlying mechanisms in the treatment of human gastric cancer are unknown. This study aimed to investigate the effects of danusertib on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition and the molecular mechanisms involved in human gastric cancer AGS and NCI-N78 cells. The results showed that danusertib had potent growth-inhibitory, apoptosis-inducing, and autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways as well as activation of 5′ AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression

  10. The Structure of Dasatinib (BNS-354825) Bound to Activated ABL Kinase Domain Elucidates its Inhibitory Activity Against Imatinib-Resistant ABL Mutants

    SciTech Connect

    Tokarski,J.; Newitt, J.; Chang, C.; Cheng, J.; Wittekind, M.; Kiefer, S.; Kish, K.; Lee, F.; Borzilerri, R.; et al.

    2006-01-01

    Chronic myeloid leukemia (CML) is caused by the constitutively activated tyrosine kinase breakpoint cluster (BCR)-ABL. Current frontline therapy for CML is imatinib, an inhibitor of BCR-ABL. Although imatinib has a high rate of clinical success in early phase CML, treatment resistance is problematic, particularly in later stages of the disease, and is frequently mediated by mutations in BCR-ABL. Dasatinib (BMS-354825) is a multitargeted tyrosine kinase inhibitor that targets oncogenic pathways and is a more potent inhibitor than imatinib against wild-type BCR-ABL. It has also shown preclinical activity against all but one of the imatinib-resistant BCR-ABL mutants tested to date. Analysis of the crystal structure of dasatinib-bound ABL kinase suggests that the increased binding affinity of dasatinib over imatinib is at least partially due to its ability to recognize multiple states of BCR-ABL. The structure also provides an explanation for the activity of dasatinib against imatinib-resistant BCR-ABL mutants.

  11. Galectin-3: a novel substrate for c-Abl kinase

    PubMed Central

    Balan, Vitaly; Nangia-Makker, Pratima; Jung, Young Suk; Wang, Yi; Raz, Avraham

    2010-01-01

    Galectin-3, a ß-galactoside-binding lectin, is found in cellular and extracellular location of the cell and has pleiotropic biological functions such as cell growth, cell adhesion and cell-cell interaction. It may exhibit anti or pro-apoptotic activity depending on its localization and post-translational modifications. Two important post-translational modifications of galectin-3 have been reported: its cleavage and phosphorylation. Cleavage of galectin-3 was reported to be involved with angiogenic potential and apoptotic resistance. Phosphorylation of galectin-3 regulates its sugar-binding ability. In this report we have identified novel tyrosine phosphorylation sites in galectin-3 as well as the kinase responsible for its phosphorylation. Our results demonstrate that tyrosines at position 79, 107 and 118 can be phosphorylated in vitro and in vivo by c-Abl kinase. Tyrosine 107 is the main target of c-Abl. Expression of galectin-3 Y107F mutant in galectin-3 null SK-Br-3 cells leads to morphological changes and increased motility compared to wild type galectin-3. Further investigation is needed to better understand the functional significance of the novel tyrosine phosphorylated sites of galectin-3. PMID:20600357

  12. Probing the Binding Site of Abl Tyrosine Kinase Using in Situ Click Chemistry

    PubMed Central

    2013-01-01

    Modern combinatorial chemistry is used to discover compounds with desired function by an alternative strategy, in which the biological target is directly involved in the choice of ligands assembled from a pool of smaller fragments. Herein, we present the first experimental result where the use of in situ click chemistry has been successfully applied to probe the ligand-binding site of Abl and the ability of this enzyme to form its inhibitor. Docking studies show that Abl is able to allow the in situ click chemistry between specific azide and alkyne fragments by binding to Abl-active sites. This report allows medicinal chemists to use protein-directed in situ click chemistry for exploring the conformational space of a ligand-binding pocket and the ability of the protein to guide its inhibitor. This approach can be a novel, valuable tool to guide drug design synthesis in the field of tyrosine kinases. PMID:24900659

  13. Productive Replication of Ebola Virus Is Regulated by the c-Abl1 Tyrosine Kinase

    PubMed Central

    García, Mayra; Cooper, Arik; Shi, Wei; Bornmann, William; Carrion, Ricardo; Kalman, Daniel; Nabel, Gary J.

    2016-01-01

    Ebola virus causes a fulminant infection in humans resulting in diffuse bleeding, vascular instability, hypotensive shock, and often death. Because of its high mortality and ease of transmission from human to human, Ebola virus remains a biological threat for which effective preventive and therapeutic interventions are needed. An understanding of the mechanisms of Ebola virus pathogenesis is critical for developing antiviral therapeutics. Here, we report that productive replication of Ebola virus is modulated by the c-Abl1 tyrosine kinase. Release of Ebola virus–like particles (VLPs) in a cell culture cotransfection system was inhibited by c-Abl1–specific small interfering RNA (siRNA) or by Abl-specific kinase inhibitors and required tyrosine phosphorylation of the Ebola matrix protein VP40. Expression of c-Abl1 stimulated an increase in phosphorylation of tyrosine 13 (Y13) of VP40, and mutation of Y13 to alanine decreased the release of Ebola VLPs. Productive replication of the highly pathogenic Ebola virus Zaire strain was inhibited by c-Abl1–specific siRNAs or by the Abl-family inhibitor nilotinib by up to four orders of magnitude. These data indicate that c-Abl1 regulates budding or release of filoviruses through a mechanism involving phosphorylation of VP40. This step of the virus life cycle therefore may represent a target for antiviral therapy. PMID:22378924

  14. Productive replication of Ebola virus is regulated by the c-Abl1 tyrosine kinase.

    PubMed

    García, Mayra; Cooper, Arik; Shi, Wei; Bornmann, William; Carrion, Ricardo; Kalman, Daniel; Nabel, Gary J

    2012-02-29

    Ebola virus causes a fulminant infection in humans resulting in diffuse bleeding, vascular instability, hypotensive shock, and often death. Because of its high mortality and ease of transmission from human to human, Ebola virus remains a biological threat for which effective preventive and therapeutic interventions are needed. An understanding of the mechanisms of Ebola virus pathogenesis is critical for developing antiviral therapeutics. Here, we report that productive replication of Ebola virus is modulated by the c-Abl1 tyrosine kinase. Release of Ebola virus-like particles (VLPs) in a cell culture cotransfection system was inhibited by c-Abl1-specific small interfering RNA (siRNA) or by Abl-specific kinase inhibitors and required tyrosine phosphorylation of the Ebola matrix protein VP40. Expression of c-Abl1 stimulated an increase in phosphorylation of tyrosine 13 (Y(13)) of VP40, and mutation of Y(13) to alanine decreased the release of Ebola VLPs. Productive replication of the highly pathogenic Ebola virus Zaire strain was inhibited by c-Abl1-specific siRNAs or by the Abl-family inhibitor nilotinib by up to four orders of magnitude. These data indicate that c-Abl1 regulates budding or release of filoviruses through a mechanism involving phosphorylation of VP40. This step of the virus life cycle therefore may represent a target for antiviral therapy.

  15. Bcr-Abl ubiquitination and Usp9x inhibition block kinase signaling and promote CML cell apoptosis.

    PubMed

    Sun, Hanshi; Kapuria, Vaibhav; Peterson, Luke F; Fang, Dexing; Bornmann, William G; Bartholomeusz, Geoffrey; Talpaz, Moshe; Donato, Nicholas J

    2011-03-17

    Although chronic myelogenous leukemia (CML) is effectively controlled by Bcr-Abl kinase inhibitors, resistance to inhibitors, progressive disease, and incomplete eradication of Bcr-Abl-expressing cells are concerns for the long-term control and suppression of this disease. We describe a novel approach to targeting key proteins in CML cells with a ubiquitin-cycle inhibitor, WP1130. Bcr-Abl is rapidly modified with K63-linked ubiquitin polymers in WP1130-treated CML cells, resulting in its accumulation in aggresomes, where is it unable to conduct signal transduction. Induction of apoptosis because of aggresomal compartmentalization of Bcr-Abl was observed in both imatinib-sensitive and -resistant cells. WP1130, but not Bcr-Abl kinase inhibitors, directly inhibits Usp9x deubiquitinase activity, resulting in the down-regulation of the prosurvival protein Mcl-1 and facilitating apoptosis. These results demonstrate that ubiquitin-cycle inhibition represents a novel and effective approach to blocking Bcr-Abl kinase signaling and reducing Mcl-1 levels to engage CML cell apoptosis. This approach may be a therapeutic option for kinase inhibitor-resistant CML patients.

  16. c-Abl Inhibitors Enable Insights into the Pathophysiology and Neuroprotection in Parkinson’s Disease

    PubMed Central

    Lindholm, Dan; Pham, Dan D.; Cascone, Annunziata; Eriksson, Ove; Wennerberg, Krister; Saarma, Mart

    2016-01-01

    Parkinson’s disease (PD) is a progressive neurodegenerative disorder causing movement disabilities and several non-motor symptoms in afflicted patients. Recent studies in animal models of PD and analyses of brain specimen from PD patients revealed an increase in the level and activity of the non-receptor tyrosine kinase Abelson (c-Abl) in dopaminergic neurons with phosphorylation of protein substrates, such as α-synuclein and the E3 ubiquitin ligase, Parkin. Most significantly inhibition of c-Abl kinase activity by small molecular compounds used in the clinic to treat human leukemia have shown promising neuroprotective effects in cell and animal models of PD. This has raised hope that similar beneficial outcome may also be observed in the treatment of PD patients by using c-Abl inhibitors. Here we highlight the background for the current optimism, reviewing c-Abl and its relationship to pathophysiological pathways prevailing in PD, as well as discussing issues related to the pharmacology and safety of current c-Abl inhibitors. Clearly more rigorously controlled and well-designed trials are needed before the c-Abl inhibitors can be used in the neuroclinic to possibly benefit an increasing number of PD patients. PMID:27833551

  17. shRNA library screening identifies nucleocytoplasmic transport as a mediator of BCR-ABL1 kinase-independent resistance

    PubMed Central

    Khorashad, Jamshid S.; Eiring, Anna M.; Mason, Clinton C.; Gantz, Kevin C.; Bowler, Amber D.; Redwine, Hannah M.; Yu, Fan; Kraft, Ira L.; Pomicter, Anthony D.; Reynolds, Kimberly R.; Iovino, Anthony J.; Zabriskie, Matthew S.; Heaton, William L.; Tantravahi, Srinivas K.; Kauffman, Michael; Shacham, Sharon; Chenchik, Alex; Bonneau, Kyle; Ullman, Katharine S.; O’Hare, Thomas

    2015-01-01

    The mechanisms underlying tyrosine kinase inhibitor (TKI) resistance in chronic myeloid leukemia (CML) patients lacking explanatory BCR-ABL1 kinase domain mutations are incompletely understood. To identify mechanisms of TKI resistance that are independent of BCR-ABL1 kinase activity, we introduced a lentiviral short hairpin RNA (shRNA) library targeting ∼5000 cell signaling genes into K562R, a CML cell line with BCR-ABL1 kinase-independent TKI resistance expressing exclusively native BCR-ABL1. A customized algorithm identified genes whose shRNA-mediated knockdown markedly impaired growth of K562R cells compared with TKI-sensitive controls. Among the top candidates were 2 components of the nucleocytoplasmic transport complex, RAN and XPO1 (CRM1). shRNA-mediated RAN inhibition or treatment of cells with the XPO1 inhibitor, KPT-330 (Selinexor), increased the imatinib sensitivity of CML cell lines with kinase-independent TKI resistance. Inhibition of either RAN or XPO1 impaired colony formation of CD34+ cells from newly diagnosed and TKI-resistant CML patients in the presence of imatinib, without effects on CD34+ cells from normal cord blood or from a patient harboring the BCR-ABL1T315I mutant. These data implicate RAN in BCR-ABL1 kinase-independent imatinib resistance and show that shRNA library screens are useful to identify alternative pathways critical to drug resistance in CML. PMID:25573989

  18. shRNA library screening identifies nucleocytoplasmic transport as a mediator of BCR-ABL1 kinase-independent resistance.

    PubMed

    Khorashad, Jamshid S; Eiring, Anna M; Mason, Clinton C; Gantz, Kevin C; Bowler, Amber D; Redwine, Hannah M; Yu, Fan; Kraft, Ira L; Pomicter, Anthony D; Reynolds, Kimberly R; Iovino, Anthony J; Zabriskie, Matthew S; Heaton, William L; Tantravahi, Srinivas K; Kauffman, Michael; Shacham, Sharon; Chenchik, Alex; Bonneau, Kyle; Ullman, Katharine S; O'Hare, Thomas; Deininger, Michael W

    2015-03-12

    The mechanisms underlying tyrosine kinase inhibitor (TKI) resistance in chronic myeloid leukemia (CML) patients lacking explanatory BCR-ABL1 kinase domain mutations are incompletely understood. To identify mechanisms of TKI resistance that are independent of BCR-ABL1 kinase activity, we introduced a lentiviral short hairpin RNA (shRNA) library targeting ∼5000 cell signaling genes into K562(R), a CML cell line with BCR-ABL1 kinase-independent TKI resistance expressing exclusively native BCR-ABL1. A customized algorithm identified genes whose shRNA-mediated knockdown markedly impaired growth of K562(R) cells compared with TKI-sensitive controls. Among the top candidates were 2 components of the nucleocytoplasmic transport complex, RAN and XPO1 (CRM1). shRNA-mediated RAN inhibition or treatment of cells with the XPO1 inhibitor, KPT-330 (Selinexor), increased the imatinib sensitivity of CML cell lines with kinase-independent TKI resistance. Inhibition of either RAN or XPO1 impaired colony formation of CD34(+) cells from newly diagnosed and TKI-resistant CML patients in the presence of imatinib, without effects on CD34(+) cells from normal cord blood or from a patient harboring the BCR-ABL1(T315I) mutant. These data implicate RAN in BCR-ABL1 kinase-independent imatinib resistance and show that shRNA library screens are useful to identify alternative pathways critical to drug resistance in CML.

  19. Constitutively active ABL family kinases, TEL/ABL and TEL/ARG, harbor distinct leukemogenic activities in vivo.

    PubMed

    Yokota, A; Hirai, H; Shoji, T; Maekawa, T; Okuda, K

    2017-04-07

    ABL (ABL1) and ARG (ABL2) are highly homologous to each other in overall domain structure and amino acid sequence, with the exception of their C-termini. As with ABL, translocations that fuse ARG to ETV6/TEL have been identified in patients with leukemia. To assess the in vivo leukemogenic activity of constitutively active ABL and ARG, we generated a bone marrow (BM) transplantation model using the chimeric forms TEL/ABL and TEL/ARG, which have comparable kinase activities. TEL/ABL rapidly induced fatal myeloid leukemia in recipient mice, whereas recipients of TEL/ARG-transduced cells did not develop myeloid leukemia; instead, they succumbed to a long-latency infiltrative mastocytosis that could be adoptively transferred to secondary recipients. Swapping of the C-termini of ABL and ARG altered disease latency and phenotypes. In a detailed in vitro study, TEL/ARG strongly promoted mast cell differentiation in response to SCF or IL-3, whereas TEL/ABL preferentially induced myeloid differentiation of hematopoietic stem/progenitor cells. These results indicate that ABL and ARG kinase activate distinct differentiation pathways to induce specific diseases in vivo, i.e., myeloid leukemia and mastocytosis, respectively. Further elucidation of the differences in their properties should provide important insight into the pathogenic mechanisms of oncogenes of the ABL kinase family.Leukemia accepted article preview online, 07 April 2017. doi:10.1038/leu.2017.114.

  20. Discovery of 3-[2-(imidazo[1,2-b]pyridazin-3-yl)ethynyl]-4-methyl-N-{4-[(4-methylpiperazin-1-yl)methyl]-3-(trifluoromethyl)phenyl}benzamide (AP24534), a potent, orally active pan-inhibitor of breakpoint cluster region-abelson (BCR-ABL) kinase including the T315I gatekeeper mutant.

    PubMed

    Huang, Wei-Sheng; Metcalf, Chester A; Sundaramoorthi, Raji; Wang, Yihan; Zou, Dong; Thomas, R Mathew; Zhu, Xiaotian; Cai, Lisi; Wen, David; Liu, Shuangying; Romero, Jan; Qi, Jiwei; Chen, Ingrid; Banda, Geetha; Lentini, Scott P; Das, Sasmita; Xu, Qihong; Keats, Jeff; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Marc I; Russian, Karin; Zhou, Tianjun; Commodore, Lois; Narasimhan, Narayana I; Mohemmad, Qurish K; Iuliucci, John; Rivera, Victor M; Dalgarno, David C; Sawyer, Tomi K; Clackson, Tim; Shakespeare, William C

    2010-06-24

    In the treatment of chronic myeloid leukemia (CML) with BCR-ABL kinase inhibitors, the T315I gatekeeper mutant has emerged as resistant to all currently approved agents. This report describes the structure-guided design of a novel series of potent pan-inhibitors of BCR-ABL, including the T315I mutation. A key structural feature is the carbon-carbon triple bond linker which skirts the increased bulk of Ile315 side chain. Extensive SAR studies led to the discovery of development candidate 20g (AP24534), which inhibited the kinase activity of both native BCR-ABL and the T315I mutant with low nM IC(50)s, and potently inhibited proliferation of corresponding Ba/F3-derived cell lines. Daily oral administration of 20g significantly prolonged survival of mice injected intravenously with BCR-ABL(T315I) expressing Ba/F3 cells. These data, coupled with a favorable ADME profile, support the potential of 20g to be an effective treatment for CML, including patients refractory to all currently approved therapies.

  1. Tyrosine Kinase Inhibitors in Lung Cancer

    PubMed Central

    Thomas, Anish; Rajan, Arun; Giaccone, Giuseppe

    2012-01-01

    SYNOPSIS ‘Driver mutations’ are essential for carcinogenesis as well as tumor progression as they confer a selective growth advantage to cancer cells. Identification of driver mutations in growth related protein kinases, especially tyrosine kinases have led to clinical development of an array of tyrosine kinase inhibitors in various malignancies, including lung cancer. Inhibition of epidermal growth factor receptor and anaplastic lymphoma kinase tyrosine kinases have proven to be of meaningful clinical benefit, while inhibition of several other tyrosine kinases have been of limited clinical benefit, thus far. An improved understanding of tyrosine kinase biology has also led to faster drug development, identification of resistance mechanisms and ways to overcome resistance. In this review, we discuss the clinical data supporting the use and practical aspects of management of patients on epidermal growth factor receptor and anaplastic lymphoma kinase tyrosine kinase inhibitors. PMID:22520981

  2. Aurora kinase inhibitors as anticancer molecules.

    PubMed

    Katayama, Hiroshi; Sen, Subrata

    2010-01-01

    Aurora kinase family of serine/threonine kinases are important regulators of mitosis that are frequently over expressed in human cancers and have been implicated in oncogenic transformation including development of chromosomal instability in cancer cells. In humans, among the three members of the kinase family, Aurora-A, -B and -C, only Aurora-A and -B are expressed at detectable levels in all somatic cells undergoing mitotic cell division and have been characterized in greater detail for their involvement in cellular pathways relevant to the development of cancer associated phenotypes. Aurora-A and -B are being investigated as potential targets for anticancer therapy. Development of inhibitors against Aurora kinases as anticancer molecules gained attention because of the facts that aberrant expression of these kinases leads to chromosomal instability and derangement of multiple tumor suppressor and oncoprotein regulated pathways. Preclinical studies and early phase I and II clinical trials of multiple Aurora kinase inhibitors as targeted anticancer drugs have provided encouraging results. This article discusses functional involvement of Aurora kinase-A and -B in the regulation of cancer relevant cellular phenotypes together with findings on some of the better characterized Aurora kinase inhibitors in modulating the functional interactions of Aurora kinases. Future possibilities about developing next generation Aurora kinase inhibitors and their clinical utility as anticancer therapeutic drugs are also discussed.

  3. Aurora Kinase inhibitors as Anticancer Molecules

    PubMed Central

    Katayama, Hiroshi; Sen, Subrata

    2015-01-01

    Aurora kinase family of serine/threonine kinases are important regulators of mitosis that are frequently over expressed in human cancers and have been implicated in oncogenic transformation including development of chromosomal instability in cancer cells. In humans, among the three members of the kinase family, Aurora-A, -B and -C, only Aurora-A and -B are expressed in detectable levels in somatic cells undergoing mitotic cell division and have been characterized in greater detail for their involvement in cellular pathways relevant to the development of cancer associated phenotypes. Aurora-A and -B are being investigated as potential targets for anticancer therapy. Development of inhibitors against Aurora kinases as anticancer molecules gained attention because of the facts that aberrant expression of these kinases lead to chromosomal instability and derangement of multiple tumor suppressor and oncoprotein regulated pathways. Pre-clinical studies and early phase I and II clinical trials of multiple Aurora kinase inhibitors as targeted anticancer drugs have provided encouraging results. This article discusses functional involvement of Aurora kinase-A and -B in the regulation of cancer relevant cellular phenotypes together with findings on some of the better characterized Aurora kinase inhibitors in modulating the functional interactions of Aurora kinases. Future possibilities about developing next generation Aurora kinase inhibitors and their clinical utility as anticancer therapeutic drugs are also discussed. PMID:20863917

  4. Structural Analysis of DFG-in and DFG-out Dual Src-Abl Inhibitors Sharing a Common Vinyl Purine Template

    SciTech Connect

    Zhou, Tianjun; Commodore, Lois; Huang, Wei-Sheng; Wang, Yihan; Sawyer, Tomi K.; Shakespeare, William C.; Clackson, Tim; Zhu, Xiaotian; Dalgarno, David C.

    2010-09-30

    Bcr-Abl is the oncogenic protein tyrosine kinase responsible for chronic myeloid leukemia (CML). Treatment of the disease with imatinib (Gleevec) often results in drug resistance via kinase mutations at the advanced phases of the disease, which has necessitated the development of new mutation-resistant inhibitors, notably against the T315I gatekeeper mutation. As part of our efforts to discover such mutation resistant Abl inhibitors, we have focused on optimizing purine template kinase inhibitors, leading to the discovery of potent DFG-in and DFG-out series of Abl inhibitors that are also potent Src inhibitors. Here we present crystal structures of Abl bound by two such inhibitors, based on a common N9-arenyl purine, and that represent both DFG-in and -out binding modes. In each structure the purine template is bound deeply in the adenine pocket and the novel vinyl linker forms a non-classical hydrogen bond to the gatekeeper residue, Thr315. Specific template substitutions promote either a DFG-in or -out binding mode, with the kinase binding site adjusting to optimize molecular recognition. Bcr-Abl T315I mutant kinase is resistant to all currently marketed Abl inhibitors, and is the focus of intense drug discovery efforts. Notably, our DFG-out inhibitor, AP24163, exhibits modest activity against this mutant, illustrating that this kinase mutant can be inhibited by DFG-out class inhibitors. Furthermore our DFG-out inhibitor exhibits dual Src-Abl activity, absent from the prototypical DFG-out inhibitor, imatinib as well as its analog, nilotinib. The data presented here provides structural guidance for the further design of novel potent DFG-out class inhibitors against Src, Abl and Abl T315I mutant kinases.

  5. Ocular Toxicity of Tyrosine Kinase Inhibitors

    PubMed Central

    Davis, Mary Elizabeth

    2016-01-01

    Purpose/Objectives To review common tyrosine kinase inhibitors, as well as their ocular side effects and management. Data Sources A comprehensive literature search was conducted using cINahl®, Pubmed, and cochrane databases for articles published since 2004 with the following search terms: ocular toxicities, tyrosine kinase inhibitors, ophthalmology, adverse events, eye, and vision. Data Synthesis Tyrosine kinase inhibitors can cause significant eye toxicity. Conclusions Given the prevalence of new tyrosine kinase inhibitor therapies and the complexity of possible pathogenesis of ocular pathology, oncology nurses can appreciate the occurrence of ocular toxicities and the role of nursing in the management of these problems. Implications for Nursing Knowledge of the risk factors and etiology of ocular toxicity of targeted cancer therapies can guide nursing assessment, enhance patient education, and improve care management. Including a review of eye symptoms and vision issues in nursing assessment can enhance early detection and treatment of ocular toxicity. PMID:26906134

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

    DTIC Science & Technology

    2014-10-01

    kinase . This grant proposal will explore the resistance to small molecule AKT protein kinase inhibitors mediated by the... molecule AKT protein kinase inhibitors is potentially mediated by the Pim-1 protein kinase , and that unique Pim protein kinase inhibitors that can in...application is essential for the development of this combined chemotherapeutic strategy. 15. SUBJECT TERMS Small Molecule AKT Inhibitors ,

  7. The STAT5 inhibitor pimozide decreases survival of chronic myelogenous leukemia cells resistant to kinase inhibitors

    PubMed Central

    Nelson, Erik A.; Walker, Sarah R.; Weisberg, Ellen; Bar-Natan, Michal; Barrett, Rosemary; Gashin, Laurie B.; Terrell, Shariya; Klitgaard, Josephine L.; Santo, Loredana; Addorio, Martha R.; Ebert, Benjamin L.; Griffin, James D.

    2011-01-01

    The transcription factor STAT5 is an essential mediator of the pathogenesis of chronic myelogenous leukemia (CML). In CML, the BCR/ABL fusion kinase causes the constitutive activation of STAT5, thereby driving the expression of genes promoting survival. BCR/ABL kinase inhibitors have become the mainstay of therapy for CML, although CML cells can develop resistance through mutations in BCR/ABL. To overcome this problem, we used a cell-based screen to identify drugs that inhibit STAT-dependent gene expression. Using this approach, we identified the psychotropic drug pimozide as a STAT5 inhibitor. Pimozide decreases STAT5 tyrosine phosphorylation, although it does not inhibit BCR/ABL or other tyrosine kinases. Furthermore, pimozide decreases the expression of STAT5 target genes and induces cell cycle arrest and apoptosis in CML cell lines. Pimozide also selectively inhibits colony formation of CD34+ bone marrow cells from CML patients. Importantly, pimozide induces similar effects in the presence of the T315I BCR/ABL mutation that renders the kinase resistant to presently available inhibitors. Simultaneously inhibiting STAT5 with pimozide and the kinase inhibitors imatinib or nilotinib shows enhanced effects in inhibiting STAT5 phosphorylation and in inducing apoptosis. Thus, targeting STAT5 may be an effective strategy for the treatment of CML and other myeloproliferative diseases. PMID:21233313

  8. The Abl and Arg kinases mediate distinct modes of phagocytosis and are required for maximal Leishmania infection.

    PubMed

    Wetzel, Dawn M; McMahon-Pratt, Diane; Koleske, Anthony J

    2012-08-01

    Leishmania, an obligate intracellular parasite, binds several receptors to trigger engulfment by phagocytes, leading to cutaneous or visceral disease. These receptors include complement receptor 3 (CR3), used by promastigotes, and the Fc receptor (FcR), used by amastigotes. The mechanisms mediating uptake are not well understood. Here we show that Abl family kinases mediate both phagocytosis and the uptake of Leishmania amazonensis by macrophages (Ms). Imatinib, an Abl/Arg kinase inhibitor, decreases opsonized polystyrene bead phagocytosis and Leishmania uptake. Interestingly, phagocytosis of IgG-coated beads is decreased in Arg-deficient Ms, while that of C3bi-coated beads is unaffected. Conversely, uptake of C3bi-coated beads is decreased in Abl-deficient Ms, but that of IgG-coated beads is unaffected. Consistent with these results, Abl-deficient Ms are inefficient at C3bi-opsonized promastigote uptake, and Arg-deficient Ms are defective in IgG1-opsonized amastigote uptake. Finally, genetic loss of Abl or Arg reduces infection severity in murine cutaneous leishmaniasis, and imatinib treatment results in smaller lesions with fewer parasites than in controls. Our studies are the first to demonstrate that efficient phagocytosis and maximal Leishmania infection require Abl family kinases. These results highlight Abl family kinase-mediated signaling pathways as potential therapeutic targets for leishmaniasis.

  9. Exploring the scaffold universe of kinase inhibitors.

    PubMed

    Hu, Ye; Bajorath, Jürgen

    2015-01-08

    The scaffold concept was applied to systematically determine, analyze, and compare core structures of kinase inhibitors. From publicly available inhibitors of the human kinome, scaffolds and cyclic skeletons were systematically extracted and organized taking activity data, structural relationships, and retrosynthetic criteria into account. Scaffold coverage varied greatly across the kinome, and many scaffolds representing compounds with different activity profiles were identified. The majority of kinase inhibitor scaffolds were involved in well-defined yet distinct structural relationships, which had different consequences on compound activity. Scaffolds exclusively representing highly potent compounds were identified as well as structurally analogous scaffolds with very different degrees of promiscuity. Scaffold relationships presented herein suggest a variety of hypotheses for inhibitor design. Our detailed organization of the kinase inhibitor scaffold universe with respect to different activity and structural criteria, all scaffolds, and the original compound data assembled for our analysis are made freely available.

  10. Aurora Kinase Inhibitors: Current Status and Outlook.

    PubMed

    Bavetsias, Vassilios; Linardopoulos, Spiros

    2015-01-01

    The Aurora kinase family comprises of cell cycle-regulated serine/threonine kinases important for mitosis. Their activity and protein expression are cell cycle regulated, peaking during mitosis to orchestrate important mitotic processes including centrosome maturation, chromosome alignment, chromosome segregation, and cytokinesis. In humans, the Aurora kinase family consists of three members; Aurora-A, Aurora-B, and Aurora-C, which each share a conserved C-terminal catalytic domain but differ in their sub-cellular localization, substrate specificity, and function during mitosis. In addition, Aurora-A and Aurora-B have been found to be overexpressed in a wide variety of human tumors. These observations led to a number of programs among academic and pharmaceutical organizations to discovering small molecule Aurora kinase inhibitors as anti-cancer drugs. This review will summarize the known Aurora kinase inhibitors currently in the clinic, and discuss the current and future directions.

  11. Aurora Kinase Inhibitors: Current Status and Outlook

    PubMed Central

    Bavetsias, Vassilios; Linardopoulos, Spiros

    2015-01-01

    The Aurora kinase family comprises of cell cycle-regulated serine/threonine kinases important for mitosis. Their activity and protein expression are cell cycle regulated, peaking during mitosis to orchestrate important mitotic processes including centrosome maturation, chromosome alignment, chromosome segregation, and cytokinesis. In humans, the Aurora kinase family consists of three members; Aurora-A, Aurora-B, and Aurora-C, which each share a conserved C-terminal catalytic domain but differ in their sub-cellular localization, substrate specificity, and function during mitosis. In addition, Aurora-A and Aurora-B have been found to be overexpressed in a wide variety of human tumors. These observations led to a number of programs among academic and pharmaceutical organizations to discovering small molecule Aurora kinase inhibitors as anti-cancer drugs. This review will summarize the known Aurora kinase inhibitors currently in the clinic, and discuss the current and future directions. PMID:26734566

  12. Regulation of DNA damage-induced apoptosis by the c-Abl tyrosine kinase

    PubMed Central

    Yuan, Zhi-Min; Huang, Yinyin; Ishiko, Takatoshi; Kharbanda, Surender; Weichselbaum, Ralph; Kufe, Donald

    1997-01-01

    Activation of the c-Abl protein tyrosine kinase by certain DNA-damaging agents contributes to down-regulation of Cdk2 and G1 arrest by a p53-dependent mechanism. The present work investigates the potential role of c-Abl in apoptosis induced by DNA damage. Transient transfection studies with wild-type, but not kinase-inactive, c-Abl demonstrate induction of apoptosis. Cells that stably express inactive c-Abl exhibit resistance to ionizing radiation-induced loss of clonogenic survival and apoptosis. Cells null for c-abl are also impaired in the apoptotic response to ionizing radiation. We further show that cells deficient in p53 undergo apoptosis in response to expression of c-Abl and exhibit decreases in radiation-induced apoptosis when expressing inactive c-Abl. These findings suggest that c-Abl kinase regulates DNA damage-induced apoptosis. PMID:9037071

  13. Activation of the c-abl oncogene by viral transduction or chromosomal translocation generates altered c-abl proteins with similar in vitro kinase properties.

    PubMed Central

    Davis, R L; Konopka, J B; Witte, O N

    1985-01-01

    The v-abl protein of Abelson murine leukemia virus is a tyrosine-specific kinase. Its normal cellular homolog, murine c-abl, does not possess detectable tyrosine kinase activity in vitro. Previously, we have detected tyrosine kinase activity in vitro for an altered c-abl gene product (c-abl P210) in the K562 human chronic myelogenous leukemia cell line. The expression of this variant c-abl gene product correlates with chromosomal translocation and amplification of the c-abl gene in K562 cells. Like v-abl, c-abl P210 is a fusion protein containing non-abl sequences near the amino terminus of c-abl. We compared the in vitro tyrosine kinase activity of c-abl P210 with that of wild-type murine v-abl. The remarkable similarities of these two proteins with respect to cis-acting autophosphorylation, trans-acting phosphorylation of exogenous substrates, and kinase inhibition, using site-directed abl-specific antisera, suggested that c-abl P210 could function similarly to v-abl in vivo. In addition, c-abl P210 possessed an associated serine kinase activity in immunoprecipitates. The serine kinase activity was not inhibited by site-directed, abl-specific antisera that inhibit the tyrosine kinase activity, suggesting that the serine kinase activity is not an intrinsic property of c-abl P210. Thus, the activation of the c-abl gene in a human leukemia cell line may have functional consequences analogous to activation of the c-abl gene in Abelson murine leukemia virus. Images PMID:4039028

  14. Computational Analysis of the Binding Specificity of Gleevec to Abl, c-Kit, Lck, and c-Src Tyrosine Kinases

    PubMed Central

    Lin, Yen-Lin; Roux, Benoît

    2013-01-01

    Gleevec, a well-known cancer therapeutic agent, is an effective inhibitor of several tyrosine kinases, including Abl and c-Kit. But it displays less potency to inhibit closely homologous tyrosine kinases, such as Lck and c-Src. Because many structural features of the binding site are highly conserved in these highly homologous kinases, the molecular determinants responsible for the binding specificity of Gleevec remain poorly understood. To address this issue, free energy perturbation molecular dynamics (FEP/MD) simulations with explicit solvent was used to compute the binding affinity of Gleevec to Abl, c-Kit, Lck, and c-Src. The results of the FEP/MD calculations are in good agreement with experiments, enabling a detailed and quantitative dissection of the absolute binding free energy in terms of various thermodynamic contributions affecting the binding specificity of Gleevec to the kinases. Dominant binding free energy contributions arises from the van der Waals dispersive interaction, compensating about two-third of the unfavorable free energy penalty associated with the loss of translational, rotational, and conformational freedom of the ligand upon binding. In contrast, the contributions from electrostatic and repulsive interactions nearly cancel out due to solvent effects. Furthermore, the calculations show the importance of the conformation of the activation loop. Among the kinases examined, Abl provides the most favorable binding environment for Gleevec via optimal protein-ligand interactions and a small free energy cost for loss of the translational, rotational, and conformational freedom upon ligand binding. The FEP/MD calculations additionally reveal that Lck and c-Src provide similar non-binding interactions with the bound-Gleevec, but the former pays less entropic penalty for the ligand losing its translational, rotational, and conformational motions to bind, examining the empirically observed differential binding affinities of Gleevec between the two

  15. AP24534, a Pan-BCR-ABL Inhibitor for Chronic Myeloid Leukemia, Potently Inhibits the T315I Mutant and Overcomes Mutation-Based Resistance

    SciTech Connect

    O’Hare, Thomas; Shakespeare, William C.; Zhu, Xiaotian; Eide, Christopher A.; Rivera, Victor M.; Wang, Frank; Adrian, Lauren T.; Zhou, Tianjun; Huang, Wei-Sheng; Xu, Qihong; Metcalf, III, Chester A.; Tyner, Jeffrey W.; Loriaux, Marc M.; Corbin, Amie S.; Wardwell, Scott; Ning, Yaoyu; Keats, Jeffrey A.; Wang, Yihan; Sundaramoorthi, Raji; Thomas, Mathew; Zhou, Dong; Snodgrass, Joseph; Commodore, Lois; Sawyer, Tomi K.; Dalgarno, David C.; Deininger, Michael W.N.; Druker, Brian J.; Clackson, Tim

    2010-09-07

    Inhibition of BCR-ABL by imatinib induces durable responses in many patients with chronic myeloid leukemia (CML), but resistance attributable to kinase domain mutations can lead to relapse and a switch to second-line therapy with nilotinib or dasatinib. Despite three approved therapeutic options, the cross-resistant BCR-ABL{sup T315I} mutation and compound mutants selected on sequential inhibitor therapy remain major clinical challenges. We report design and preclinical evaluation of AP24534, a potent, orally available multitargeted kinase inhibitor active against T315I and other BCR-ABL mutants. AP24534 inhibited all tested BCR-ABL mutants in cellular and biochemical assays, suppressed BCR-ABL{sup T315I}-driven tumor growth in mice, and completely abrogated resistance in cell-based mutagenesis screens. Our work supports clinical evaluation of AP24534 as a pan-BCR-ABL inhibitor for treatment of CML.

  16. Combinations of Novel Histone Deacetylase and Bcr-Abl Inhibitors in the Therapy of Imatinib Mesylate-Sensitive and Refractory Bcr-Abl Expressing Leukemia

    DTIC Science & Technology

    2007-03-01

    Kumaraswamy S, Boyapalle S, Rocha K , Wu J, Atadja P, Manley P, and Bhalla K . Combined effects of novel tyrosine kinase inhibitor AMN107 and histone...Manley, F. Giles and K . Bhalla. Combined effects of novel tyrosine kinase inhibitor AMN107 and histone deacetylase inhibitor LBH589 against unmutated...20 Supplement), 2006: 6592 3. H. M. Kantarjian, N. Gattermann, S. G. O’Brien, K . Bhalla, A. Hochhaus, F. Cervantes, L. Alland, O. Ottmann, F

  17. Tyrosine kinase inhibitors in preclinical development.

    PubMed

    Levitt, M L; Koty, P P

    1999-01-01

    Due to the limited efficacy of cytotoxic chemotherapy in the treatment of advanced malignancy and its excessive toxicity precluding its use in chemoprevention, new therapeutic and preventive strategies have been sought. One of the most interesting of these new approaches is the manipulation of signal transduction pathways. Among the approaches being considered to eventuate such a strategy is the inhibition of autophosphorylation, a critical first step in the signal transduction pathways of many cell surface receptor tyrosine kinases, as well as of non-receptor tyrosine kinases. This article is intended to review those tyrosine kinase inhibitors that are currently in preclinical development, for which there are data to support consideration for their use in chemoprevention or cancer treatment. We will focus upon those agents that have received attention in the past several years.

  18. Tyrosine Kinase Inhibitors and Diabetes: A Novel Treatment Paradigm?

    PubMed

    Fountas, Athanasios; Diamantopoulos, Leonidas-Nikolaos; Tsatsoulis, Agathocles

    2015-11-01

    Deregulation of protein tyrosine kinase (PTK) activity is implicated in various proliferative conditions. Multi-target tyrosine kinase inhibitors (TKIs) are increasingly used for the treatment of different malignancies. Recently, several clinical cases of the reversal of both type 1 and 2 diabetes mellitus (T1DM, T2DM) during TKI administration have been reported. Experimental in vivo and in vitro studies have elucidated some of the mechanisms behind this effect. For example, inhibition of Abelson tyrosine kinase (c-Abl) results in β cell survival and enhanced insulin secretion, while platelet-derived growth factor receptor (PDGFR) and epidermal growth factor receptor (EGFR) inhibition leads to improvement in insulin sensitivity. In addition, inhibition of vascular endothelial growth factor receptor 2 (VEGFR2) reduces the degree of islet cell inflammation (insulitis). Therefore, targeting several PTKs may provide a novel approach for correcting the pathophysiologic disturbances of diabetes.

  19. Combined Targeting of BCL-2 and BCR-ABL Tyrosine Kinase Eradicates Chronic Myeloid Leukemia Stem Cells

    PubMed Central

    Mak, Po Yee; Mu, Hong; Zhou, Hongsheng; Mak, Duncan H.; Schober, Wendy; Leverson, Joel D.; Zhang, Bin; Bhatia, Ravi; Huang, Xuelin; Cortes, Jorge; Kantarjian, Hagop; Konopleva, Marina

    2016-01-01

    BCR-ABL tyrosine kinase inhibitors (TKIs) are effective against chronic myeloid leukemia (CML), but they rarely eliminate CML stem cells. Disease relapse is common upon therapy cessation, even in patients with complete molecular responses. Furthermore, once CML progresses to blast crisis (BC), treatment outcomes are dismal. We hypothesized that concomitant targeting of BCL-2 and BCR-ABL tyrosine kinase could overcome these limitations. We demonstrate increased BCL-2 expression at the protein level in bone marrow cells, particularly in Lin−Sca-1+cKit+ cells of inducible CML in mice as determined by CyTOF mass cytometry. Further, selective inhibition of BCL-2, aided by TKI-mediated MCL-1 and BCL-XL inhibition, markedly decreased leukemic Lin−Sca-1+cKit+ cell numbers and long-term stem cell frequency, and prolonged survival in a murine CML model. Additionally, this combination effectively eradicated CD34+CD38−, CD34+CD38+, and quiescent stem/progenitor CD34+ cells from BC CML patient samples. Our results suggest that BCL-2 is a key survival factor for CML stem/progenitor cells and that combined inhibition of BCL-2 and BCR-ABL tyrosine kinase has the potential to significantly improve depth of response and cure rates of chronic phase and BC CML. PMID:27605552

  20. Direct interactions with the integrin β1 cytoplasmic tail activate the Abl2/Arg kinase.

    PubMed

    Simpson, Mark A; Bradley, William D; Harburger, David; Parsons, Maddy; Calderwood, David A; Koleske, Anthony J

    2015-03-27

    Integrins are heterodimeric α/β extracellular matrix adhesion receptors that couple physically to the actin cytoskeleton and regulate kinase signaling pathways to control cytoskeletal remodeling and adhesion complex formation and disassembly. β1 integrins signal through the Abl2/Arg (Abl-related gene) nonreceptor tyrosine kinase to control fibroblast cell motility, neuronal dendrite morphogenesis and stability, and cancer cell invasiveness, but the molecular mechanisms by which integrin β1 activates Arg are unknown. We report here that the Arg kinase domain interacts directly with a lysine-rich membrane-proximal segment in the integrin β1 cytoplasmic tail, that Arg phosphorylates the membrane-proximal Tyr-783 in the β1 tail, and that the Arg Src homology domain then engages this phosphorylated region in the tail. We show that these interactions mediate direct binding between integrin β1 and Arg in vitro and in cells and activate Arg kinase activity. These findings provide a model for understanding how β1-containing integrins interact with and activate Abl family kinases.

  1. Neuroprotective efficacy of a new brain-penetrating C-Abl inhibitor in a murine Parkinson's disease model.

    PubMed

    Imam, Syed Z; Trickler, William; Kimura, Shinya; Binienda, Zbigniew K; Paule, Merle G; Slikker, William; Li, Senlin; Clark, Robert A; Ali, Syed F

    2013-01-01

    Experimental evidence suggests that oxidative and nitrative mechanisms account for much of the dopaminergic neuronal injury in Parkinson's disease (PD). The ubiquitously expressed non-receptor tyrosine kinase c-Abl is activated by oxidative stress and thus, may play a role in redox-mediated neurodegeneration. Recently, we reported that c-Abl is activated in PD and that a c-Abl inhibitor mitigated neuronal damage in a PD animal model, suggesting a novel neuroprotective therapeutic approach. In the studies presented here, we evaluated the efficacy of a potent and clinically relevant second-generation irreversible Abl kinase inhibitor, INNO-406, as a therapeutic agent for PD. Our studies reveal that INNO-406 is capable of preventing the progression of dopaminergic neuronal damage in a toxin-induced C57 mouse model of PD. Using bovine brain microvessel endothelium as an in vitro blood-brain barrier (BBB) model, we detected rapid and significant transfer of INNO-406. Additionally, pharmacokinetic analyses demonstrated significant nanomolar concentrations of INNO-406 in brain in the presence or absence of MPTP administration, however, INNO-406 did not alter the brain levels of MPP+ in MPTP-treated mice. Finally, we showed that 10 mg/kg of INNO-406 given to C57 mice for one week before MPTP treatment (4×20 mg/kg i.p., every 2 h) and then for one week after MPTP treatment decreased the loss of dopamine in the striatum by 45% and the loss of TH+ neurons in substantia nigra pars compacts by 40%. This treatment regimen also abrogated activation of c-Abl, tyrosine phosphorylation of the Abl substrate and E3-ubiquitin ligase parkin, and accumulation of the toxic parkin substrate AIMP2. We propose that compounds of the INNO-406 class of Abl inhibitors will be useful new neuroprotective drugs for the treatment of PD-like pathology in preclinical systems that should be easily translated to the clinic.

  2. Novel protein kinase C inhibitors: alpha-terthiophene derivatives.

    PubMed

    Kim, D S; Ashendel, C L; Zhou, Q; Chang, C T; Lee, E S; Chang, C J

    1998-10-06

    A series of alpha-terthiophene derivatives were prepared and their protein kinase C inhibitory activity were evaluated. The aldehyde derivatives were most potent inhibitors (IC50 < 1 microM). alpha-Terthiophene monoaldehyde was inactive in the inhibitions of protein kinase A, mitogen activated protein kinase and protein tyrosine kinase.

  3. AP24534, a Pan-BCR-ABL Inhibitor for Chronic Myeloid Leukemia, Potently Inhibits the T315I Mutant and Overcomes Mutation-Based Resistance

    PubMed Central

    O’Hare, Thomas; Shakespeare, William C.; Zhu, Xiaotian; Eide, Christopher A.; Rivera, Victor M.; Wang, Frank; Adrian, Lauren T.; Zhou, Tianjun; Huang, Wei-Sheng; Xu, Qihong; Metcalf, Chester A.; Tyner, Jeffrey W.; Loriaux, Marc M.; Corbin, Amie S.; Wardwell, Scott; Ning, Yaoyu; Keats, Jeffrey A.; Wang, Yihan; Sundaramoorthi, Raji; Thomas, Mathew; Zhou, Dong; Snodgrass, Joseph; Commodore, Lois; Sawyer, Tomi K.; Dalgarno, David C.; Deininger, Michael W.N.; Druker, Brian J.; Clackson, Tim

    2009-01-01

    SUMMARY Inhibition of BCR-ABL by imatinib induces durable responses in many patients with chronic myeloid leukemia (CML), but resistance attributable to kinase domain mutations can lead to relapse and a switch to second-line therapy with nilotinib or dasatinib. Despite three approved therapeutic options, the cross-resistant BCR-ABLT315I mutation and compound mutants selected on sequential inhibitor therapy remain major clinical challenges. We report design and pre-clinical evaluation of AP24534, a potent, orally available multi-targeted kinase inhibitor active against T315I and other BCR-ABL mutants. AP24534 inhibited all tested BCR-ABL mutants in cellular and biochemical assays, suppressed BCR-ABLT315I-driven tumor growth in mice, and completely abrogated resistance in cell-based mutagenesis screens. Our work supports clinical evaluation of AP24534 as a pan-BCR-ABL inhibitor for treatment of CML. PMID:19878872

  4. Adaptation of the plasma inhibitory activity assay to detect Aurora, ABL and FLT3 kinase inhibition by AT9283 in pediatric leukemia.

    PubMed

    Podesta, Jennifer E; Sugar, Richard; Squires, Matt; Linardopoulos, Spiros; Pearson, Andrew D J; Moore, Andrew S

    2011-09-01

    Non-invasive assessment of biomarker modulation is important for evaluating targeted therapeutics, particularly in pediatrics. The plasma inhibitory activity (PIA) assay is used clinically to assess FLT3 inhibition ex vivo and guide dosing. AT9283 is a novel Aurora kinase inhibitor with secondary activity against FLT3 and ABL. We adapted the PIA assay to simultaneously detect inhibition of Aurora and FLT3 in AML, and Aurora and ABL in CML by AT9283. Furthermore, we optimized the assay for children, where limited blood volumes are available for pharmacodynamic studies. Simultaneously detecting multiple kinase inhibition may identify important mechanisms of action for novel anti-leukemic drugs.

  5. Functional interaction between nonreceptor tyrosine kinase c-Abl and SR-Rich protein RBM39.

    PubMed

    Mai, Sanyue; Qu, Xiuhua; Li, Ping; Ma, Qingjun; Liu, Xuan; Cao, Cheng

    2016-04-22

    RBM39, also known as splicing factor HCC1.4, acts as a transcriptional coactivator for the steroid nuclear receptors JUN/AP-1, ESR1/ER-α and ESR2/ER-β. RBM39 is involved in the regulation of the transcriptional responses of these steroid nuclear receptors and promotes transcriptional initiation. In this paper, we report that RBM39 interacts with the nonreceptor tyrosine kinase c-Abl. Both the Src homology (SH) 2 and SH3 domains of c-Abl interact with RBM39. The major tyrosine phosphorylation sites on RBM39 that are phosphorylated by c-Abl are Y95 and Y99, as demonstrated by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) and mutational analysis. c-Abl was shown boost the transcriptional coactivation activity of RBM39 for ERα and PRβ in a tyrosine kinase-dependent manner. The results suggest that mammalian c-Abl plays an important role in steroid hormone receptor-mediated transcription by regulating RBM39.

  6. Rapid Discovery and Structure–Activity Relationships of Pyrazolopyrimidines That Potently Suppress Breast Cancer Cell Growth via SRC Kinase Inhibition with Exceptional Selectivity over ABL Kinase

    PubMed Central

    2016-01-01

    Novel pyrazolopyrimidines displaying high potency and selectivity toward SRC family kinases have been developed by combining ligand-based design and phenotypic screening in an iterative manner. Compounds were derived from the promiscuous kinase inhibitor PP1 to search for analogs that could potentially target a broad spectrum of kinases involved in cancer. Phenotypic screening against MCF7 mammary adenocarcinoma cells generated target-agnostic structure–activity relationships that biased subsequent designs toward breast cancer treatment rather than to a particular target. This strategy led to the discovery of two potent antiproliferative leads with phenotypically distinct anticancer mode of actions. Kinase profiling and further optimization resulted in eCF506, the first small molecule with subnanomolar IC50 for SRC that requires 3 orders of magnitude greater concentration to inhibit ABL. eCF506 exhibits excellent water solubility, an optimal DMPK profile and oral bioavailability, halts SRC-associated neuromast migration in zebrafish embryos without inducing life-threatening heart defects, and inhibits SRC phosphorylation in tumor xenografts in mice. PMID:27115835

  7. Virtual screening of Abl inhibitors from large compound libraries by support vector machines.

    PubMed

    Liu, X H; Ma, X H; Tan, C Y; Jiang, Y Y; Go, M L; Low, B C; Chen, Y Z

    2009-09-01

    Abl promotes cancers by regulating cell morphogenesis, motility, growth, and survival. Successes of several marketed and clinical trial Abl inhibitors against leukemia and other cancers and appearances of reduced efficacies and drug resistances have led to significant interest in and efforts for developing new Abl inhibitors. In silico methods of pharmacophore, fragment, and molecular docking have been used in some of these efforts. It is desirable to explore other in silico methods capable of searching large compound libraries at high yields and reduced false-hit rates. We evaluated support vector machines (SVM) as a virtual screening tool for searching Abl inhibitors from large compound libraries. SVM trained and tested by 708 inhibitors and 65,494 putative noninhibitors correctly identified 84.4 to 92.3% inhibitors and 99.96 to 99.99% noninhibitors in 5-fold cross validation studies. SVM trained by 708 pre-2008 inhibitors and 65 494 putative noninhibitors correctly identified 50.5% of the 91 inhibitors reported since 2008 and predicted as inhibitors 29,072 (0.21%) of 13.56M PubChem, 659 (0.39%) of 168K MDDR, and 330 (5.0%) of 6638 MDDR compounds similar to the known inhibitors. SVM showed comparable yields and substantially reduced false-hit rates against two similarity based and another machine learning VS methods based on the same training and testing data sets and molecular descriptors. These suggest that SVM is capable of searching Abl inhibitors from large compound libraries at low false-hit rates.

  8. Anchor-based classification and type-C inhibitors for tyrosine kinases

    PubMed Central

    Hsu, Kai-Cheng; Sung, Tzu-Ying; Lin, Chih-Ta; Chiu, Yi-Yuan; Hsu, John T.-A.; Hung, Hui-Chen; Sun, Chung-Ming; Barve, Indrajeet; Chen, Wen-Liang; Huang, Wen-Chien; Huang, Chin-Ting; Chen, Chun-Hwa; Yang, Jinn-Moon

    2015-01-01

    Tyrosine kinases regulate various biological processes and are drug targets for cancers. At present, the design of selective and anti-resistant inhibitors of kinases is an emergent task. Here, we inferred specific site-moiety maps containing two specific anchors to uncover a new binding pocket in the C-terminal hinge region by docking 4,680 kinase inhibitors into 51 protein kinases, and this finding provides an opportunity for the development of kinase inhibitors with high selectivity and anti-drug resistance. We present an anchor-based classification for tyrosine kinases and discover two type-C inhibitors, namely rosmarinic acid (RA) and EGCG, which occupy two and one specific anchors, respectively, by screening 118,759 natural compounds. Our profiling reveals that RA and EGCG selectively inhibit 3% (EGFR and SYK) and 14% of 64 kinases, respectively. According to the guide of our anchor model, we synthesized three RA derivatives with better potency. These type-C inhibitors are able to maintain activities for drug-resistant EGFR and decrease the invasion ability of breast cancer cells. Our results show that the type-C inhibitors occupying a new pocket are promising for cancer treatments due to their kinase selectivity and anti-drug resistance. PMID:26077136

  9. Activation of tyrosine kinase c-Abl contributes to α-synuclein–induced neurodegeneration

    PubMed Central

    Lee, Su Hyun; Kim, Donghoon; Karuppagounder, Senthilkumar S.; Kumar, Manoj; Mao, Xiaobo; Shin, Joo Ho; Lee, Yunjong; Pletnikova, Olga; Troncoso, Juan C.; Dawson, Valina L.; Dawson, Ted M.; Ko, Han Seok

    2016-01-01

    Aggregation of α-synuclein contributes to the formation of Lewy bodies and neurites, the pathologic hallmarks of Parkinson disease (PD) and α-synucleinopathies. Although a number of human mutations have been identified in familial PD, the mechanisms that promote α-synuclein accumulation and toxicity are poorly understood. Here, we report that hyperactivity of the nonreceptor tyrosine kinase c-Abl critically regulates α-synuclein–induced neuropathology. In mice expressing a human α-synucleinopathy–associated mutation (hA53Tα-syn mice), deletion of the gene encoding c-Abl reduced α-synuclein aggregation, neuropathology, and neurobehavioral deficits. Conversely, overexpression of constitutively active c-Abl in hA53Tα-syn mice accelerated α-synuclein aggregation, neuropathology, and neurobehavioral deficits. Moreover, c-Abl activation led to an age-dependent increase in phosphotyrosine 39 α-synuclein. In human postmortem samples, there was an accumulation of phosphotyrosine 39 α-synuclein in brain tissues and Lewy bodies of PD patients compared with age-matched controls. Furthermore, in vitro studies show that c-Abl phosphorylation of α-synuclein at tyrosine 39 enhances α-synuclein aggregation. Taken together, this work establishes a critical role for c-Abl in α-synuclein–induced neurodegeneration and demonstrates that selective inhibition of c-Abl may be neuroprotective. This study further indicates that phosphotyrosine 39 α-synuclein is a potential disease indicator for PD and related α-synucleinopathies. PMID:27348587

  10. Tyrosine kinase c-Abl regulates the survival of plasma cells.

    PubMed

    Li, Yan-Feng; Xu, Shengli; Huang, Yuhan; Ou, Xijun; Lam, Kong-Peng

    2017-01-06

    Tyrosine kinase c-Abl plays an important role in early B cell development. Its deletion leads to reduced pro- and pre-B cell generation in mice. However, its function in B cell terminal differentiation remains unexplored. Here, we used c-Abl(f/f) Aicda(cre/+) mice, in which c-Abl is ablated only in antigen-activated B cells, to study the role of c-Abl in germinal center (GC) B and antibody-secreting plasma cell formation. Upon challenge with a model antigen, we found normal GC and memory B but reduced plasma cells and antigen-specific antibody response in the mutant mice. In-vitro studies revealed that plasma cells lacking c-Abl could be generated but did not accumulate in culture, indicative of survival defect. They also exhibited impaired STAT3 phosphorylation. The plasma cell defects could be rectified by introduction of Bim-deficiency or delivery of colivelin, a STAT3 activator, into c-Abl(f/f) Aicda(cre/+) mice. Hence, c-Abl signalling regulates the survival of plasma cells.

  11. Discovery and Characterization of a Cell-Permeable, Small-Molecule c-Abl Kinase Activator that Binds to the Myristoyl Binding Site

    SciTech Connect

    Yang, Jingsong; Campobasso, Nino; Biju, Mangatt P.; Fisher, Kelly; Pan, Xiao-Qing; Cottom, Josh; Galbraith, Sarah; Ho, Thau; Zhang, Hong; Hong, Xuan; Ward, Paris; Hofmann, Glenn; Siegfried, Brett; Zappacosta, Francesca; Washio, Yoshiaki; Cao, Ping; Qu, Junya; Bertrand, Sophie; Wang, Da-Yuan; Head, Martha S.; Li, Hu; Moores, Sheri; Lai, Zhihong; Johanson, Kyung; Burton, George; Erickson-Miller, Connie; Simpson, Graham; Tummino, Peter; Copeland, Robert A.; Oliff, Allen

    2014-10-02

    c-Abl kinase activity is regulated by a unique mechanism involving the formation of an autoinhibited conformation in which the N-terminal myristoyl group binds intramolecularly to the myristoyl binding site on the kinase domain and induces the bending of the {alpha}I helix that creates a docking surface for the SH2 domain. Here, we report a small-molecule c-Abl activator, DPH, that displays potent enzymatic and cellular activity in stimulating c-Abl activation. Structural analyses indicate that DPH binds to the myristoyl binding site and prevents the formation of the bent conformation of the {alpha}I helix through steric hindrance, a mode of action distinct from the previously identified allosteric c-Abl inhibitor, GNF-2, that also binds to the myristoyl binding site. DPH represents the first cell-permeable, small-molecule tool compound for c-Abl activation.

  12. Targeting cancer with small-molecular-weight kinase inhibitors.

    PubMed

    Fabbro, Doriano; Cowan-Jacob, Sandra W; Möbitz, Henrik; Martiny-Baron, Georg

    2012-01-01

    Protein and lipid kinases fulfill essential roles in many signaling pathways that regulate normal cell functions. Deregulation of these kinase activities lead to a variety of pathologies ranging from cancer to inflammatory diseases, diabetes, infectious diseases, cardiovascular disorders, cell growth and survival. 518 protein kinases and about 20 lipid-modifying kinases are encoded by the human genome, and a much larger proportion of additional kinases are present in parasite, bacterial, fungal, and viral genomes that are susceptible to exploitation as drug targets. Since many human diseases result from overactivation of protein and lipid kinases due to mutations and/or overexpression, this enzyme class represents an important target for the pharmaceutical industry. Approximately one third of all protein targets under investigation in the pharmaceutical industry are protein or lipid kinases.The kinase inhibitors that have been launched, thus far, are mainly in oncology indications and are directed against a handful of protein and lipid kinases. With one exception, all of these registered kinase inhibitors are directed toward the ATP-site and display different selectivities, potencies, and pharmacokinetic properties. At present, about 150 kinase-targeted drugs are in clinical development and many more in various stages of preclinical development. Kinase inhibitor drugs that are in clinical trials target all stages of signal transduction from the receptor protein tyrosine kinases that initiate intracellular signaling, through second-messenger-dependent lipid and protein kinases, and protein kinases that regulate the cell cycle.This review provides an insight into protein and lipid kinase drug discovery with respect to achievements, binding modes of inhibitors, and novel avenues for the generation of second-generation kinase inhibitors to treat cancers.

  13. Structural investigation of protein kinase C inhibitors.

    PubMed

    Barak, D; Shibata, M; Rein, R

    1991-01-01

    The phospholipid and Ca2+ dependent protein kinase (PKC) plays an essential role in a variety of cellular events. Inhibition of PKC was shown to arrest growth in tumor cell cultures making it a target for possible antitumor therapy. Calphostins are potent inhibitors of PKC with high affinity for the enzyme regulatory site. Structural characteristics of calphostins, which confer the inhibitory activity, are investigated by comparing their optimized structures with the existing models for PKC activation. The resulting model of inhibitory activity assumes interaction with two out of the three electrostatic interaction sites postulated for activators. The model shows two sites of hydrophobic interaction and enables the inhibitory activity of gossypol to be accounted for.

  14. Structural investigation of protein kinase C inhibitors

    NASA Technical Reports Server (NTRS)

    Barak, D.; Shibata, M.; Rein, R.

    1991-01-01

    The phospholipid and Ca2+ dependent protein kinase (PKC) plays an essential role in a variety of cellular events. Inhibition of PKC was shown to arrest growth in tumor cell cultures making it a target for possible antitumor therapy. Calphostins are potent inhibitors of PKC with high affinity for the enzyme regulatory site. Structural characteristics of calphostins, which confer the inhibitory activity, are investigated by comparing their optimized structures with the existing models for PKC activation. The resulting model of inhibitory activity assumes interaction with two out of the three electrostatic interaction sites postulated for activators. The model shows two sites of hydrophobic interaction and enables the inhibitory activity of gossypol to be accounted for.

  15. Tyrosine kinase c-Abl regulates the survival of plasma cells

    PubMed Central

    Li, Yan-Feng; Xu, Shengli; Huang, Yuhan; Ou, Xijun; Lam, Kong-Peng

    2017-01-01

    Tyrosine kinase c-Abl plays an important role in early B cell development. Its deletion leads to reduced pro- and pre-B cell generation in mice. However, its function in B cell terminal differentiation remains unexplored. Here, we used c-Ablf/f Aicdacre/+ mice, in which c-Abl is ablated only in antigen-activated B cells, to study the role of c-Abl in germinal center (GC) B and antibody-secreting plasma cell formation. Upon challenge with a model antigen, we found normal GC and memory B but reduced plasma cells and antigen-specific antibody response in the mutant mice. In-vitro studies revealed that plasma cells lacking c-Abl could be generated but did not accumulate in culture, indicative of survival defect. They also exhibited impaired STAT3 phosphorylation. The plasma cell defects could be rectified by introduction of Bim-deficiency or delivery of colivelin, a STAT3 activator, into c-Ablf/f Aicdacre/+ mice. Hence, c-Abl signalling regulates the survival of plasma cells. PMID:28057924

  16. In-silico identification of inhibitors against mutated BCR-ABL protein of chronic myeloid leukemia: a virtual screening and molecular dynamics simulation study.

    PubMed

    Kumar, Himansu; Raj, Utkarsh; Gupta, Saurabh; Varadwaj, Pritish Kumar

    2016-10-01

    Aberrant and proliferative expression of the oncogene BCR-ABL in the bone marrow cells had been proven as the prime cause of chronic myeloid leukemia (CML). It has been established that tyrosine kinase domain of BCR-ABL protein is a potential therapeutic target for the treatment of CML. Imatinib is considered as a first-generation drug that can inhibit the enzymatic action by inhibiting the ATP binding with BCR-ABL protein. Later on, insensitivity of CML cells towards Imatinib has been observed may be due to mutation in tyrosine kinase domain of the ABL receptor. Subsequently, some other second-generation drugs have also been reported viz. Baustinib, Nilotinib, Dasatinib, Ponatinib, Bafetinib, etc., which can able to combat against mutated domain of ABL tyrosine kinase protein. By taking into account of bioavailability and resistance developed, there is an utmost need to find some more inhibitors for the mutated ABL tyrosine kinase protein. For virtual screening, a data-set has been generated by collecting the all available drug like natural compounds from ZINC and Drug Bank databases. Comparative docking analysis was also carried out on the active site of ABL tyrosine kinase receptor with reported reference inhibitors. Molecular dynamics simulation of the best screened interacting complex was done for 50 ns to validate the stability of the system. These selected inhibitors were further validated and analyzed through pharmacokinetics properties and series of ADMET parameters by in silico methods. Considering the above said parameters proposed molecules are concluded as potential leads for drug designing pipeline against CML.

  17. VEGF165-induced vascular permeability requires NRP1 for ABL-mediated SRC family kinase activation

    PubMed Central

    Lampropoulou, Anastasia; Senatore, Valentina; Brash, James T.; Liyanage, Sidath E.; Raimondi, Claudio; Bainbridge, James W.

    2017-01-01

    The vascular endothelial growth factor (VEGF) isoform VEGF165 stimulates vascular growth and hyperpermeability. Whereas blood vessel growth is essential to sustain organ health, chronic hyperpermeability causes damaging tissue edema. By combining in vivo and tissue culture models, we show here that VEGF165-induced vascular leakage requires both VEGFR2 and NRP1, including the VEGF164-binding site of NRP1 and the NRP1 cytoplasmic domain (NCD), but not the known NCD interactor GIPC1. In the VEGF165-bound receptor complex, the NCD promotes ABL kinase activation, which in turn is required to activate VEGFR2-recruited SRC family kinases (SFKs). These results elucidate the receptor complex and signaling hierarchy of downstream kinases that transduce the permeability response to VEGF165. In a mouse model with choroidal neovascularisation akin to age-related macular degeneration, NCD loss attenuated vessel leakage without affecting neovascularisation. These findings raise the possibility that targeting NRP1 or its NCD interactors may be a useful therapeutic strategy in neovascular disease to reduce VEGF165-induced edema without compromising vessel growth. PMID:28289053

  18. Glycogen synthase kinase-3 inhibitors: Rescuers of cognitive impairments

    PubMed Central

    King, Margaret K.; Pardo, Marta; Cheng, Yuyan; Downey, Kimberlee; Jope, Richard S.; Beurel, Eléonore

    2013-01-01

    Impairment of cognitive processes is a devastating outcome of many diseases, injuries, and drugs affecting the central nervous system (CNS). Most often, very little can be done by available therapeutic interventions to improve cognitive functions. Here we review evidence that inhibition of glycogen synthase kinase-3 (GSK3) ameliorates cognitive deficits in a wide variety of animal models of CNS diseases, including Alzheimer's disease, Fragile X syndrome, Down syndrome, Parkinson's disease, spinocerebellar ataxia type 1, traumatic brain injury, and others. GSK3 inhibitors also improve cognition following impairments caused by therapeutic interventions, such as cranial irradiation for brain tumors. These findings demonstrate that GSK3 inhibitors are able to ameliorate cognitive impairments caused by a diverse array of diseases, injury, and treatments. The improvements in impaired cognition instilled by administration of GSK3 inhibitors appear to involve a variety of different mechanisms, such as supporting long-term potentiation and diminishing long-term depression, promotion of neurogenesis, reduction of inflammation, and increasing a number of neuroprotective mechanisms. The potential for GSK3 inhibitors to repair cognitive deficits associated with many conditions warrants further investigation of their potential for therapeutic interventions, particularly considering the current dearth of treatments available to reduce loss of cognitive functions. PMID:23916593

  19. In Vitro Characterization of Derrone as an Aurora Kinase Inhibitor.

    PubMed

    Hoang, Nhung Thi My; Phuong, Thuong Thien; Nguyen, Trang Thi Nhu; Tran, Yen Thi Hai; Nguyen, Anh Thi Ngoc; Nguyen, Thanh Lai; Bui, Khanh Thi Van

    2016-06-01

    Among mitotic kinases, Aurora kinases are the most widely studied, since their expression is restricted to mitosis. They play a key role in chromosome segregation and cell polyploidy. Aurora kinases are important therapeutic targets, and several research groups have directed their efforts toward the identification of kinase inhibitors. The aim of this study is to screen and characterize Aurora kinase inhibitors from natural substances extracted from plants that are used in the Vietnamese pharmacopoeia. We have characterized in vitro Derrone, extracted from Erythrina orientalis L. MURR, as a novel Aurora kinase inhibitor. This compound exhibited an ability to inhibit the phosphorylation of histone H3 at ser10 both in kinase assay and at the cellular level. The compound was more effective against Aurora kinase B, with a lower IC50 value as compared to Aurora A. Moreover, it impaired the mitotic spindle checkpoint and led to endoreduplication in cancer cells, a phenomenon caused by an Aurora B inhibitor. Interestingly, using the xCelligence system and real-time cell analysis (RTCA) software, we set up a comparison of cell proliferation profiles between cancer cells treated with Derrone and VX680-a well-known Aurora kinase inhibitor-and we found that these profiles exhibited considerable similarity in cell morphology, growth, and death. Additionally, Derrone significantly inhibited the formation and growth of MCF7 tumor spheroids.

  20. Kinase inhibitor profiling reveals unexpected opportunities to inhibit disease-associated mutant kinases

    PubMed Central

    Duong-Ly, Krisna C.; Devarajan, Karthik; Liang, Shuguang; Horiuchi, Kurumi Y.; Wang, Yuren; Ma, Haiching; Peterson, Jeffrey R.

    2016-01-01

    Summary Small-molecule kinase inhibitors have typically been designed to inhibit wild-type kinases rather than the mutant forms that frequently arise in diseases such as cancer. Mutations can have serious clinical implications by increasing kinase catalytic activity or conferring therapeutic resistance. To identify opportunities to repurpose inhibitors against disease-associated mutant kinases, we conducted a large-scale functional screen of 183 known kinase inhibitors against 76 recombinant, mutant kinases. The results revealed lead compounds with activity against clinically important mutant kinases including ALK, LRRK2, RET, and EGFR as well as unexpected opportunities for repurposing FDA-approved kinase inhibitors as leads for additional indications. Furthermore, using T674I PDGFRα as an example, we show how single-dose screening data can provide predictive structure-activity data to guide subsequent inhibitor optimization. This study provides a resource for the development of inhibitors against numerous disease-associated mutant kinases and illustrates the potential of unbiased profiling as an approach to compound-centric inhibitor development. PMID:26776524

  1. Skin problems and EGFR-tyrosine kinase inhibitor

    PubMed Central

    Kozuki, Toshiyuki

    2016-01-01

    Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. PMID:26826719

  2. Skin problems and EGFR-tyrosine kinase inhibitor.

    PubMed

    Kozuki, Toshiyuki

    2016-04-01

    Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities.

  3. Stat3 contributes to resistance toward BCR-ABL inhibitors in a bone marrow microenvironment model of drug resistance

    PubMed Central

    Bewry, Nadine N.; Nair, Rajesh R.; Emmons, Michael F.; Boulware, David; Pinilla-Ibarz, Javier; Hazlehurst, Lori A.

    2009-01-01

    Imatinib mesylate is a potent, molecularly targeted therapy against the oncogenic tyrosine kinase BCR-ABL. Although imatinib mesylate has considerable efficacy against chronic myeloid leukemia (CML), advanced-stage CML patients frequently become refractory to this agent. The bone marrow is the predominant microenvironment of CML and is a rich source of both soluble factors and extracellular matrices, which may influence drug response. To address the influence of the bone marrow microenvironment on imatinib mesylate sensitivity, we used an in vitro coculture bone marrow stroma model. Our data show culturing K562 cells, in bone marrow stroma-derived conditioned medium (CM), is sufficient to cause resistance to BCR-ABL inhibitors. Drug resistance correlated with increased pTyrStat3, whereas no increases in pTyrStat5 were noted. Moreover, resistance was associated with increased levels of the Stat3 target genes Bcl-xl, Mcl-1, and survivin. Finally, reducing Stat3 levels with small interfering RNA sensitized K562 cells cultured in CM to imatinib mesylate-induced cell death. Importantly, Stat3 dependency was specific for cells grown in CM, as reducing Stat3 levels in regular growth conditions had no effect on imatinib mesylate sensitivity. Together, these data support a novel mechanism of BCR-ABL-independent imatinib mesylate resistance and provide preclinical rationale for using Stat3 inhibitors to increase the efficacy of imatinib mesylate within the context of the bone marrow microenvironment. PMID:18852120

  4. A Novel Calcium-Dependent Kinase Inhibitor, Bumped Kinase Inhibitor 1517, Cures Cryptosporidiosis in Immunosuppressed Mice.

    PubMed

    Castellanos-Gonzalez, Alejandro; Sparks, Hayley; Nava, Samantha; Huang, Wenlin; Zhang, Zhongsheng; Rivas, Kasey; Hulverson, Matthew A; Barrett, Lynn K; Ojo, Kayode K; Fan, Erkang; Van Voorhis, Wesley C; White, Arthur Clinton

    2016-12-15

    Cryptosporidium is recognized as one of the main causes of childhood diarrhea worldwide. However, the current treatment for cryptosporidiosis is suboptimal. Calcium flux is essential for entry in apicomplexan parasites. Calcium-dependent protein kinases (CDPKs) are distinct from protein kinases of mammals, and the CDPK1 of the apicomplexan Cryptosporidium lack side chains that typically block a hydrophobic pocket in protein kinases. We exploited this to develop bumped kinase inhibitors (BKIs) that selectively target CDPK1. We have shown that several BKIs of Cryptosporidium CDPK1 potently reduce enzymatic activity and decrease parasite numbers when tested in vitro. In the present work, we studied the anticryptosporidial activity of BKI-1517, a novel BKI. The half maximal effective concentration for Cryptosporidium parvum in HCT-8 cells was determined to be approximately 50 nM. Silencing experiments of CDPK1 suggest that BKI-1517 acts on CDPK1 as its primary target. In a mouse model of chronic infection, 5 of 6 SCID/beige mice (83.3%) were cured after treatment with a single daily dose of 120 mg/kg BKI-1517. No side effects were observed. These data support advancing BKI-1517 as a lead compound for drug development for cryptosporidiosis.

  5. Therapeutic drug monitoring and tyrosine kinase inhibitors

    PubMed Central

    Herviou, Pauline; Thivat, Emilie; Richard, Damien; Roche, Lucie; Dohou, Joyce; Pouget, Mélanie; Eschalier, Alain; Durando, Xavier; Authier, Nicolas

    2016-01-01

    The therapeutic activity of drugs can be optimized by establishing an individualized dosage, based on the measurement of the drug concentration in the serum, particularly if the drugs are characterized by an inter-individual variation in pharmacokinetics that results in an under- or overexposure to treatment. In recent years, several tyrosine kinase inhibitors (TKIs) have been developed to block intracellular signaling pathways in tumor cells. These oral drugs are candidates for therapeutic drug monitoring (TDM) due to their high inter-individual variability for therapeutic and toxic effects. Following a literature search on PubMed, studies on TKIs and their pharmacokinetic characteristics, plasma quantification and inter-individual variability was studied. TDM is commonly used in various medical fields, including cardiology and psychiatry, but is not often applied in oncology. Plasma concentration monitoring has been thoroughly studied for imatinib, in order to evaluate the usefulness of TDM. The measurement of plasma concentration can be performed by various analytical techniques, with liquid chromatography-mass spectrometry being the reference method. This method is currently used to monitor the efficacy and tolerability of imatinib treatments. Although TDM is already being used for imatinib, additional studies are required in order to improve this practice with the inclusion of other TKIs. PMID:27446421

  6. Chemotherapeutic agents circumvent emergence of dasatinib-resistant BCR-ABL kinase mutations in a precise mouse model of Philadelphia chromosome-positive acute lymphoblastic leukemia.

    PubMed

    Boulos, Nidal; Mulder, Heather L; Calabrese, Christopher R; Morrison, Jeffrey B; Rehg, Jerold E; Relling, Mary V; Sherr, Charles J; Williams, Richard T

    2011-03-31

    The introduction of cultured p185(BCR-ABL)-expressing (p185+) Arf (-/-) pre-B cells into healthy syngeneic mice induces aggressive acute lymphoblastic leukemia (ALL) that genetically and phenotypically mimics the human disease. We adapted this high-throughput Philadelphia chromosome-positive (Ph(+)) ALL animal model for in vivo luminescent imaging to investigate disease progression, targeted therapeutic response, and ALL relapse in living mice. Mice bearing high leukemic burdens (simulating human Ph(+) ALL at diagnosis) entered remission on maximally intensive, twice-daily dasatinib therapy, but invariably relapsed with disseminated and/or central nervous system disease. Although relapse was frequently accompanied by the eventual appearance of leukemic clones harboring BCR-ABL kinase domain (KD) mutations that confer drug resistance, their clonal emergence required prolonged dasatinib exposure. KD P-loop mutations predominated in mice receiving less intensive therapy, whereas high-dose treatment selected for T315I "gatekeeper" mutations resistant to all 3 Food and Drug Administration-approved BCR-ABL kinase inhibitors. The addition of dexamethasone and/or L-asparaginase to reduced-intensity dasatinib therapy improved long-term survival of the majority of mice that received all 3 drugs. Although non-tumor-cell-autonomous mechanisms can prevent full eradication of dasatinib-refractory ALL in this clinically relevant model, the emergence of resistance to BCR-ABL kinase inhibitors can be effectively circumvented by the addition of "conventional" chemotherapeutic agents with alternate antileukemic mechanisms of action.

  7. BCR-ABL1 compound mutations combining key kinase domain positions confer clinical resistance to ponatinib in Ph chromosome-positive leukemia.

    PubMed

    Zabriskie, Matthew S; Eide, Christopher A; Tantravahi, Srinivas K; Vellore, Nadeem A; Estrada, Johanna; Nicolini, Franck E; Khoury, Hanna J; Larson, Richard A; Konopleva, Marina; Cortes, Jorge E; Kantarjian, Hagop; Jabbour, Elias J; Kornblau, Steven M; Lipton, Jeffrey H; Rea, Delphine; Stenke, Leif; Barbany, Gisela; Lange, Thoralf; Hernández-Boluda, Juan-Carlos; Ossenkoppele, Gert J; Press, Richard D; Chuah, Charles; Goldberg, Stuart L; Wetzler, Meir; Mahon, Francois-Xavier; Etienne, Gabriel; Baccarani, Michele; Soverini, Simona; Rosti, Gianantonio; Rousselot, Philippe; Friedman, Ran; Deininger, Marie; Reynolds, Kimberly R; Heaton, William L; Eiring, Anna M; Pomicter, Anthony D; Khorashad, Jamshid S; Kelley, Todd W; Baron, Riccardo; Druker, Brian J; Deininger, Michael W; O'Hare, Thomas

    2014-09-08

    Ponatinib is the only currently approved tyrosine kinase inhibitor (TKI) that suppresses all BCR-ABL1 single mutants in Philadelphia chromosome-positive (Ph(+)) leukemia, including the recalcitrant BCR-ABL1(T315I) mutant. However, emergence of compound mutations in a BCR-ABL1 allele may confer ponatinib resistance. We found that clinically reported BCR-ABL1 compound mutants center on 12 key positions and confer varying resistance to imatinib, nilotinib, dasatinib, ponatinib, rebastinib, and bosutinib. T315I-inclusive compound mutants confer high-level resistance to TKIs, including ponatinib. In vitro resistance profiling was predictive of treatment outcomes in Ph(+) leukemia patients. Structural explanations for compound mutation-based resistance were obtained through molecular dynamics simulations. Our findings demonstrate that BCR-ABL1 compound mutants confer different levels of TKI resistance, necessitating rational treatment selection to optimize clinical outcome.

  8. Janus kinase 2 mutations in cases with BCR-ABL-negative chronic myeloproliferative disorders from Turkey

    PubMed Central

    Yildiz, Ismail; Yokuş, Osman; Gedik, Habip

    2017-01-01

    Objective: We aimed to investigate the frequency of Janus kinase 2 (JAK2) mutations in cases with chronic myeloproliferative disorders (CMDs), and the relationship between the presence of JAK2 mutation and leukocytosis and splenomegaly, retrospectively. Materials and Methods: Patients, who were diagnosed with BCR-ABL-negative CMDs according to diagnosis criteria of the World Health Organization and followed up at the hematology clinic between 2013 and 2015, were investigated in terms of the frequency of JAK2 mutation in cases with CMDs, and the relationship between the presence of JAK2 mutation and leukocytosis and splenomegaly, retrospectively. Results: In total, 100 patients, who were diagnosed with BCR-ABL-negative CMDs, were evaluated retrospectively. The mean age of the patients with JAK2 positivity was significantly higher compared to patients with negative. JAK2-positivity rates in the age groups were significantly different. Gender, diagnosis, splenomegaly, and leukocytosis were not statistically different for JAK2 positivity between the groups. Conclusion: JAK2 V617F mutation is more commonly seen in older age as a risk for complications related to CDMS. Splenomegaly and leukocytosis are not associated with JAK2 V617F mutation. PMID:28182037

  9. T Cell Receptor-Independent Basal Signaling via Erk and Abl Kinases Suppresses RAG Gene Expression

    PubMed Central

    Roose, Jeroen P; Diehn, Maximilian; Tomlinson, Michael G; Lin, Joseph; Alizadeh, Ash A; Botstein, David; Brown, Patrick O

    2003-01-01

    Signal transduction pathways guided by cellular receptors commonly exhibit low-level constitutive signaling in a continuous, ligand-independent manner. The dynamic equilibrium of positive and negative regulators establishes such a tonic signal. Ligand-independent signaling by the precursors of mature antigen receptors regulates development of B and T lymphocytes. Here we describe a basal signal that controls gene expression profiles in the Jurkat T cell line and mouse thymocytes. Using DNA microarrays and Northern blots to analyze unstimulated cells, we demonstrate that expression of a cluster of genes, including RAG-1 and RAG-2, is repressed by constitutive signals requiring the adapter molecules LAT and SLP-76. This TCR-like pathway results in constitutive low-level activity of Erk and Abl kinases. Inhibition of Abl by the drug STI-571 or inhibition of signaling events upstream of Erk increases RAG-1 expression. Our data suggest that physiologic gene expression programs depend upon tonic activity of signaling pathways independent of receptor ligation. PMID:14624253

  10. Formation of long and winding nuclear F-actin bundles by nuclear c-Abl tyrosine kinase

    SciTech Connect

    Aoyama, Kazumasa; Yuki, Ryuzaburo; Horiike, Yasuyoshi; Kubota, Sho; Yamaguchi, Noritaka; Morii, Mariko; Ishibashi, Kenichi; Nakayama, Yuji; Kuga, Takahisa; Hashimoto, Yuuki; Tomonaga, Takeshi; Yamaguchi, Naoto

    2013-12-10

    The non-receptor-type tyrosine kinase c-Abl is involved in actin dynamics in the cytoplasm. Having three nuclear localization signals (NLSs) and one nuclear export signal, c-Abl shuttles between the nucleus and the cytoplasm. Although monomeric actin and filamentous actin (F-actin) are present in the nucleus, little is known about the relationship between c-Abl and nuclear actin dynamics. Here, we show that nuclear-localized c-Abl induces nuclear F-actin formation. Adriamycin-induced DNA damage together with leptomycin B treatment accumulates c-Abl into the nucleus and increases the levels of nuclear F-actin. Treatment of c-Abl-knockdown cells with Adriamycin and leptomycin B barely increases the nuclear F-actin levels. Expression of nuclear-targeted c-Abl (NLS-c-Abl) increases the levels of nuclear F-actin even without Adriamycin, and the increased levels of nuclear F-actin are not inhibited by inactivation of Abl kinase activity. Intriguingly, expression of NLS-c-Abl induces the formation of long and winding bundles of F-actin within the nucleus in a c-Abl kinase activity-dependent manner. Furthermore, NLS-c-AblΔC, which lacks the actin-binding domain but has the full tyrosine kinase activity, is incapable of forming nuclear F-actin and in particular long and winding nuclear F-actin bundles. These results suggest that nuclear c-Abl plays critical roles in actin dynamics within the nucleus. - Highlights: • We show the involvement of c-Abl tyrosine kinase in nuclear actin dynamics. • Nuclear F-actin is formed by nuclear-localized c-Abl and its kinase-dead version. • The c-Abl actin-binding domain is prerequisite for nuclear F-actin formation. • Formation of long nuclear F-actin bundles requires nuclear c-Abl kinase activity. • We discuss a role for nuclear F-actin bundle formation in chromatin regulation.

  11. C-Abl inhibitor imatinib enhances insulin production by β cells: c-Abl negatively regulates insulin production via interfering with the expression of NKx2.2 and GLUT-2.

    PubMed

    Xia, Chang-Qing; Zhang, Pengcheng; Li, Shiwu; Yuan, Lihui; Xia, Tina; Xie, Chao; Clare-Salzler, Michael J

    2014-01-01

    Chronic myelogenous leukemia patients treated with tyrosine kinase inhibitor, Imatinib, were shown to have increased serum levels of C-peptide. Imatinib specifically inhibits the tyrosine kinase, c-Abl. However, the mechanism of how Imatinib treatment can lead to increased insulin level is unclear. Specifically, there is little investigation into whether Imatinib directly affects β cells to promote insulin production. In this study, we showed that Imatinib significantly induced insulin expression in both glucose-stimulated and resting β cells. In line with this finding, c-Abl knockdown by siRNA and overexpression of c-Abl markedly enhanced and inhibited insulin expression in β cells, respectively. Unexpectedly, high concentrations of glucose significantly induced c-Abl expression, suggesting c-Abl may play a role in balancing insulin production during glucose stimulation. Further studies demonstrated that c-Abl inhibition did not affect the major insulin gene transcription factor, pancreatic and duodenal homeobox-1 (PDX-1) expression. Of interest, inhibition of c-Abl enhanced NKx2.2 and overexpression of c-Abl in β cells markedly down-regulated NKx2.2, which is a positive regulator for insulin gene expression. Additionally, we found that c-Abl inhibition significantly enhanced the expression of glucose transporter GLUT2 on β cells. Our study demonstrates a previously unrecognized mechanism that controls insulin expression through c-Abl-regulated NKx2.2 and GLUT2. Therapeutic targeting β cell c-Abl could be employed in the treatment of diabetes or β cell tumor, insulinoma.

  12. Second-generation inhibitors of Bruton tyrosine kinase.

    PubMed

    Wu, Jingjing; Liu, Christina; Tsui, Stella T; Liu, Delong

    2016-09-02

    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.

  13. Comprehensive characterization of the Published Kinase Inhibitor Set.

    PubMed

    Elkins, Jonathan M; Fedele, Vita; Szklarz, Marta; Abdul Azeez, Kamal R; Salah, Eidarus; Mikolajczyk, Jowita; Romanov, Sergei; Sepetov, Nikolai; Huang, Xi-Ping; Roth, Bryan L; Al Haj Zen, Ayman; Fourches, Denis; Muratov, Eugene; Tropsha, Alex; Morris, Joel; Teicher, Beverly A; Kunkel, Mark; Polley, Eric; Lackey, Karen E; Atkinson, Francis L; Overington, John P; Bamborough, Paul; Müller, Susanne; Price, Daniel J; Willson, Timothy M; Drewry, David H; Knapp, Stefan; Zuercher, William J

    2016-01-01

    Despite the success of protein kinase inhibitors as approved therapeutics, drug discovery has focused on a small subset of kinase targets. Here we provide a thorough characterization of the Published Kinase Inhibitor Set (PKIS), a set of 367 small-molecule ATP-competitive kinase inhibitors that was recently made freely available with the aim of expanding research in this field and as an experiment in open-source target validation. We screen the set in activity assays with 224 recombinant kinases and 24 G protein-coupled receptors and in cellular assays of cancer cell proliferation and angiogenesis. We identify chemical starting points for designing new chemical probes of orphan kinases and illustrate the utility of these leads by developing a selective inhibitor for the previously untargeted kinases LOK and SLK. Our cellular screens reveal compounds that modulate cancer cell growth and angiogenesis in vitro. These reagents and associated data illustrate an efficient way forward to increasing understanding of the historically untargeted kinome.

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

    PubMed

    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.

  15. Tyrosine kinase inhibitors - small molecular weight compounds inhibiting EGFR.

    PubMed

    Hegymegi-Barakonyi, Bálint; Eros, Dániel; Szántai-Kis, Csaba; Breza, Nóra; Bánhegyi, Péter; Szabó, Gábor Viktor; Várkondi, Edit; Peták, István; Orfi, László; Kéri, György

    2009-06-01

    Abnormally elevated EGFR kinase activity can lead to various pathological states, including proliferative diseases such as cancer. The development of selective protein kinase inhibitors has become an important area of drug discovery for the potential treatment of a variety of solid tumors such as breast, ovarian and colorectal cancers, NSCLC, and carcinoma of the head and neck. There are three small molecule EGFR kinase inhibitor drugs in clinical use (gefitinib, erlotinib and lapatinib), and several others are currently undergoing clinical development. This review summarizes the development of EGFR kinase inhibitors, and includes descriptions of the binding modes, the importance of a multiple-targets strategy, the effects of sensitizing and resistance mutations in the EGFR, and molecular diagnostic approaches. In addition, the use of target fishing for selectivity profiling, off-target identification and quantitative structure-activity relationship modeling for the prediction of EGFR inhibition is discussed.

  16. Inhibition of TGF-β signaling in tumor cells by small molecule Src family kinase inhibitors.

    PubMed

    Bartscht, Tobias; Rosien, Benjamin; Rades, Dirk; Kaufmann, Roland; Biersack, Harald; Lehnerta, Hendrik; Ungefroren, Hendrik

    2017-01-02

    In a series of studies carried out over the last couple of years in various cell types, it was observed that the experimentally used Src family kinase inhibitors PP1 and PP2 and the clinically used Src/Abl inhibitors AZM475271 and dasatinib are potent inhibitors of TGF-β mediated cellular responses such as Smad and p38 mitogen-activated protein kinase phosphorylation, Smad-dependent transcriptional activation, growth inhibition, epithelial-mesenchymal transition (EMT), and cell motility. While for PP1/PP2 it was demonstrated shown that these agents directly inhibit the kinase activity of the TGF-β type I receptor activin receptor-like kinase 5, the mechanism of the anti-TGF-β effect of AZM475271 and dasatinib is less clear. In contrast, the anti-TGF-β effect of yet another Src/Abl inhibitor, bosutinib, is more variable with respect to the type of the TGF-β response and the cell type affected, and lacks a clear dose-dependency. In the light of their strong anti-activin receptor-like kinase 5 kinase effect, PP1 and PP2 should not be used when studying the role of c-Src as downstream mediators in TGF-β/activin receptor-like kinase 5 signaling. On the other hand, based upon in vitro findings, it is conceivable that part of the therapeutic effects of AZM475271 and dasatinib seen in preclinical and clinical studies with solid tumors was caused by inhibition of prometastatic TGF-β rather than Src signaling. If AZM475271 and dasatinib can indeed act as dual Src / TGF-β inhibitors in vivo, this may be beneficial for prevention of metastatic disease in more advanced tumor stages.

  17. Benefits of targeting both pericytes and endothelial cells in the tumor vasculature with kinase inhibitors

    PubMed Central

    Bergers, Gabriele; Song, Steven; Meyer-Morse, Nicole; Bergsland, Emily; Hanahan, Douglas

    2003-01-01

    Functions of receptor tyrosine kinases implicated in angiogenesis were pharmacologically impaired in a mouse model of pancreatic islet cancer. An inhibitor targeting VEGFRs in endothelial cells (SU5416) is effective against early-stage angiogenic lesions, but not large, well-vascularized tumors. In contrast, a kinase inhibitor incorporating selectivity for PDGFRs (SU6668) is shown to block further growth of end-stage tumors, eliciting detachment of pericytes and disruption of tumor vascularity. Importantly, PDGFRs were expressed only in perivascular cells of this tumor type, suggesting that PDGFR+ pericytes in tumors present a complimentary target to endothelial cells for efficacious antiangiogenic therapy. Therapeutic regimes combining the two kinase inhibitors (SU5416 and SU6668) were more efficacious against all stages of islet carcinogenesis than either single agent. Combination of the VEGFR inhibitor with another distinctive kinase inhibitor targeting PDGFR activity (Gleevec) was also able to regress late-stage tumors. Thus, combinatorial targeting of receptor tyrosine kinases shows promise for treating multiple stages in tumorigenesis, most notably the often-intractable late-stage solid tumor. PMID:12727920

  18. Pyrrolopyridine inhibitors of mitogen-activated protein kinase-activated protein kinase 2 (MK-2).

    PubMed

    Anderson, David R; Meyers, Marvin J; Vernier, William F; Mahoney, Matthew W; Kurumbail, Ravi G; Caspers, Nicole; Poda, Gennadiy I; Schindler, John F; Reitz, David B; Mourey, Robert J

    2007-05-31

    A new class of potent kinase inhibitors selective for mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2 or MK-2) for the treatment of rheumatoid arthritis has been prepared and evaluated. These inhibitors have IC50 values as low as 10 nM against the target and have good selectivity profiles against a number of kinases including CDK2, ERK, JNK, and p38. These MK-2 inhibitors have been shown to suppress TNFalpha production in U397 cells and to be efficacious in an acute inflammation model. The structure-activity relationships of this series, the selectivity for MK-2 and their activity in both in vitro and in vivo models are discussed. The observed selectivity is discussed with the aid of an MK-2/inhibitor crystal structure.

  19. On-Chip Peptide Mass Spectrometry Imaging for Protein Kinase Inhibitor Screening.

    PubMed

    Cho, Young-Lai; Kim, Young-Pil; Son, Jin Gyeong; Son, Miyoung; Lee, Tae Geol

    2017-01-03

    Protein kinases are enzymes that are important targets for drug discovery because of their involvement in regulating the essential cellular processes. For this reason, the changes in protein kinase activity induced by each drug candidate (the inhibitor in this case) need to be accurately determined. Here, an on-chip secondary ion mass spectrometry (SIMS) imaging technique of the peptides was developed for determining protein kinase activity and inhibitor screening without a matrix. In our method, cysteine-tethered peptides adsorbed onto a gold surface produced changes in the relative peak intensities of the phosphorylated and unphosphorylated substrate peptides, which were quantitatively dependent on protein kinase activity. Using mass spectrometry imaging of multiple compartments on the gold surface in the presence of a peptide substrate, we screened 13,727 inhibitors, of which seven were initially found to have inhibitor efficiencies that surpassed 50%. Of these, we were able to identify a new breakpoint cluster region-abelson (BCR-ABL)(T315I) kinase inhibitor, henceforth referred to as KR135861. KR135861 showed no cytotoxicity and was subsequently confirmed to be superior to imatinib, a commercial drug marketed as Gleevec. Moreover, KR135861 exhibited a greater inhibitory effect on the BCR-ABL(T315I) tyrosine kinase, with an IC50 value as low as 1.3 μM. In in vitro experiments, KR135861 reduced the viability of both Ba/F3 cells expressing wild-type BCR-ABL and BCR-ABL(T315I), in contrast to imatinib's inhibitory effects only on Ba/F3 cells expressing wild-type BCR-ABL. Due to the surface sensitivity and selectivity of SIMS imaging, it is anticipated that our approach will make it easier to validate the small modifications of a substrate in relation to enzyme activity as well as for drug discovery. This mass spectrometry imaging analysis enables efficient screening for protein kinase inhibitors, thus permitting high-throughput drug screening with high accuracy

  20. Conformation-selective ATP-competitive inhibitors control regulatory interactions and noncatalytic functions of mitogen-activated protein kinases.

    PubMed

    Hari, Sanjay B; Merritt, Ethan A; Maly, Dustin J

    2014-05-22

    Most potent protein kinase inhibitors act by competing with ATP to block the phosphotransferase activity of their targets. However, emerging evidence demonstrates that ATP-competitive inhibitors can affect kinase interactions and functions in ways beyond blocking catalytic activity. Here, we show that stabilizing alternative ATP-binding site conformations of the mitogen-activated protein kinases (MAPKs) p38α and Erk2 with ATP-competitive inhibitors differentially, and in some cases divergently, modulates the abilities of these kinases to interact with upstream activators and deactivating phosphatases. Conformation-selective ligands are also able to modulate Erk2's ability to allosterically activate the MAPK phosphatase DUSP6, highlighting how ATP-competitive ligands can control noncatalytic kinase functions. Overall, these studies underscore the relationship between the ATP-binding and regulatory sites of MAPKs and provide insight into how ATP-competitive ligands can be designed to confer graded control over protein kinase function.

  1. NMR reveals the allosteric opening and closing of Abelson tyrosine kinase by ATP-site and myristoyl pocket inhibitors

    PubMed Central

    Skora, Lukasz; Mestan, Jürgen; Fabbro, Doriano; Jahnke, Wolfgang; Grzesiek, Stephan

    2013-01-01

    Successful treatment of chronic myelogenous leukemia is based on inhibitors binding to the ATP site of the deregulated breakpoint cluster region (Bcr)–Abelson tyrosine kinase (Abl) fusion protein. Recently, a new type of allosteric inhibitors targeting the Abl myristoyl pocket was shown in preclinical studies to overcome ATP-site inhibitor resistance arising in some patients. Using NMR and small-angle X-ray scattering, we have analyzed the solution conformations of apo Abelson tyrosine kinase (c-Abl) and c-Abl complexes with ATP-site and allosteric inhibitors. Binding of the ATP-site inhibitor imatinib leads to an unexpected open conformation of the multidomain SH3-SH2-kinase c-Abl core, whose relevance is confirmed by cellular assays on Bcr-Abl. The combination of imatinib with the allosteric inhibitor GNF-5 restores the closed, inactivated state. Our data provide detailed insights on the poorly understood combined effect of the two inhibitor types, which is able to overcome drug resistance. PMID:24191057

  2. NMR reveals the allosteric opening and closing of Abelson tyrosine kinase by ATP-site and myristoyl pocket inhibitors.

    PubMed

    Skora, Lukasz; Mestan, Jürgen; Fabbro, Doriano; Jahnke, Wolfgang; Grzesiek, Stephan

    2013-11-19

    Successful treatment of chronic myelogenous leukemia is based on inhibitors binding to the ATP site of the deregulated breakpoint cluster region (Bcr)-Abelson tyrosine kinase (Abl) fusion protein. Recently, a new type of allosteric inhibitors targeting the Abl myristoyl pocket was shown in preclinical studies to overcome ATP-site inhibitor resistance arising in some patients. Using NMR and small-angle X-ray scattering, we have analyzed the solution conformations of apo Abelson tyrosine kinase (c-Abl) and c-Abl complexes with ATP-site and allosteric inhibitors. Binding of the ATP-site inhibitor imatinib leads to an unexpected open conformation of the multidomain SH3-SH2-kinase c-Abl core, whose relevance is confirmed by cellular assays on Bcr-Abl. The combination of imatinib with the allosteric inhibitor GNF-5 restores the closed, inactivated state. Our data provide detailed insights on the poorly understood combined effect of the two inhibitor types, which is able to overcome drug resistance.

  3. Tyrosine Kinase Inhibitors and Vascular Toxicity: Impetus for a Classification System?

    PubMed

    Herrmann, Joerg

    2016-06-01

    The introduction of molecularly targeted therapies with tyrosine kinase inhibitors has revolutionized cancer therapy and has contributed to a steady decline in cancer-related mortality since the late 1990s. However, not only cardiac but also vascular toxicity has been reported for these agents, some as expected on-target effects (e.g., VEGF receptor inhibitors) and others as unanticipated events (e.g., BCR-Abl inhibitors). A sound understanding of these cardiovascular toxic effects is critical to advance mechanistic insight into vascular disease and clinical care. From a conceptual standpoint, there might be value in defining type I (permanent) and type II (transient) vascular toxicity. This review will focus on the tyrosine kinase inhibitors in current clinical use and their associated vascular side effects.

  4. Discovery and Characterization of Allosteric WNK Kinase Inhibitors.

    PubMed

    Yamada, Ken; Zhang, Ji-Hu; Xie, Xiaoling; Reinhardt, Juergen; Xie, Amy Qiongshu; LaSala, Daniel; Kohls, Darcy; Yowe, David; Burdick, Debra; Yoshisue, Hajime; Wakai, Hiromichi; Schmidt, Isabel; Gunawan, Jason; Yasoshima, Kayo; Yue, Q Kimberley; Kato, Mitsunori; Mogi, Muneto; Idamakanti, Neeraja; Kreder, Natasha; Drueckes, Peter; Pandey, Pramod; Kawanami, Toshio; Huang, Waanjeng; Yagi, Yukiko I; Deng, Zhan; Park, Hyi-Man

    2016-12-16

    Protein kinases are known for their highly conserved adenosine triphosphate (ATP)-binding site, rendering the discovery of selective inhibitors a major challenge. In theory, allosteric inhibitors can achieve high selectivity by targeting less conserved regions of the kinases, often with an added benefit of retaining efficacy under high physiological ATP concentration. Although often overlooked in favor of ATP-site directed approaches, performing a screen at high ATP concentration or stringent hit triaging with high ATP concentration offers conceptually simple methods of identifying inhibitors that bind outside the ATP pocket. Here, we applied the latter approach to the With-No-Lysine (K) (WNK) kinases to discover lead molecules for a next-generation antihypertensive that requires a stringent safety profile. This strategy yielded several ATP noncompetitive WNK1-4 kinase inhibitors, the optimization of which enabled cocrystallization with WNK1, revealing an allosteric binding mode consistent with the observed exquisite specificity for WNK1-4 kinases. The optimized compound inhibited rubidium uptake by sodium chloride cotransporter 1 (NKCC1) in HT29 cells, consistent with the reported physiology of WNK kinases in renal electrolyte handling.

  5. Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors

    PubMed Central

    Ferreira, Rubén; Nilsson, Jesper R.; Solano, Carlos; Andréasson, Joakim; Grøtli, Morten

    2015-01-01

    REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ. PMID:25944708

  6. Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ferreira, Rubén; Nilsson, Jesper R.; Solano, Carlos; Andréasson, Joakim; Grøtli, Morten

    2015-05-01

    REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ.

  7. Allosteric Small-Molecule Inhibitors of the AKT Kinase

    NASA Astrophysics Data System (ADS)

    Dalafave, D. S.

    This research addresses computational design of small druglike molecules for possible anticancer applications. AKT and SGK are kinases that control important cellular functions. They are highly homologous, having similar activators and targets. Cancers with increased SGK activity may develop resistance to AKT-specific inhibitors. Our goal was to design new molecules that would bind both AKT and SGK, thus preventing the development of drug resistance. Most kinase inhibitors target the kinase ATP-binding site. However, the high similarity in this site among kinases makes it difficult to target specifically. Furthermore, mutations in this site can cause resistance to ATP-competitive kinase inhibitors. We used existing AKT inhibitors as initial templates to design molecules that could potentially bind the allosteric sites of both AKT and SGK. Molecules with no implicit toxicities and optimal drug-like properties were used for docking studies. Binding energies of the stable complexes that the designed molecules formed with AKT and SGK were calculated. Possible applications of the designed putative inhibitors against cancers with overexpressed AKT/SGK is discussed.

  8. Computational study of Gleevec and G6G reveals molecular determinants of kinase inhibitor selectivity

    SciTech Connect

    Lin, Yen -Lin; Meng, Yilin; Huang, Lei; Roux, Benoît

    2014-10-22

    Gleevec is a potent inhibitor of Abl tyrosine kinase but not of the highly homologous c-Src kinase. Because the ligand binds to an inactive form of the protein in which an Asp-Phe-Gly structural motif along the activation loop adopts a so-called DFG-out conformation, it was suggested that binding specificity was controlled by a “conformational selection” mechanism. In this context, the binding affinity displayed by the kinase inhibitor G6G poses an intriguing challenge. Although it possesses a chemical core very similar to that of Gleevec, G6G is a potent inhibitor of both Abl and c-Src kinases. Both inhibitors bind to the DFG-out conformation of the kinases, which seems to be in contradiction with the conformational selection mechanism. To address this issue and display the hidden thermodynamic contributions affecting the binding selectivity, molecular dynamics free energy simulations with explicit solvent molecules were carried out. Relative to Gleevec, G6G forms highly favorable van der Waals dispersive interactions upon binding to the kinases via its triazine functional group, which is considerably larger than the corresponding pyridine moiety in Gleevec. Upon binding of G6G to c-Src, these interactions offset the unfavorable free energy cost of the DFG-out conformation. When binding to Abl, however, G6G experiences an unfavorable free energy penalty due to steric clashes with the phosphate-binding loop, yielding an overall binding affinity that is similar to that of Gleevec. Such steric clashes are absent when G6G binds to c-Src, due to the extended conformation of the phosphate-binding loop.

  9. Computational study of Gleevec and G6G reveals molecular determinants of kinase inhibitor selectivity

    DOE PAGES

    Lin, Yen -Lin; Meng, Yilin; Huang, Lei; ...

    2014-10-22

    Gleevec is a potent inhibitor of Abl tyrosine kinase but not of the highly homologous c-Src kinase. Because the ligand binds to an inactive form of the protein in which an Asp-Phe-Gly structural motif along the activation loop adopts a so-called DFG-out conformation, it was suggested that binding specificity was controlled by a “conformational selection” mechanism. In this context, the binding affinity displayed by the kinase inhibitor G6G poses an intriguing challenge. Although it possesses a chemical core very similar to that of Gleevec, G6G is a potent inhibitor of both Abl and c-Src kinases. Both inhibitors bind to themore » DFG-out conformation of the kinases, which seems to be in contradiction with the conformational selection mechanism. To address this issue and display the hidden thermodynamic contributions affecting the binding selectivity, molecular dynamics free energy simulations with explicit solvent molecules were carried out. Relative to Gleevec, G6G forms highly favorable van der Waals dispersive interactions upon binding to the kinases via its triazine functional group, which is considerably larger than the corresponding pyridine moiety in Gleevec. Upon binding of G6G to c-Src, these interactions offset the unfavorable free energy cost of the DFG-out conformation. When binding to Abl, however, G6G experiences an unfavorable free energy penalty due to steric clashes with the phosphate-binding loop, yielding an overall binding affinity that is similar to that of Gleevec. Such steric clashes are absent when G6G binds to c-Src, due to the extended conformation of the phosphate-binding loop.« less

  10. Fitness Conferred by BCR-ABL Kinase Domain Mutations Determines the Risk of Pre-Existing Resistance in Chronic Myeloid Leukemia

    PubMed Central

    Skaggs, Brian; Gorre, Mercedes; Sawyers, Charles L.; Michor, Franziska

    2011-01-01

    Chronic myeloid leukemia (CML) is the first human malignancy to be successfully treated with a small molecule inhibitor, imatinib, targeting a mutant oncoprotein (BCR-ABL). Despite its successes, acquired resistance to imatinib leads to reduced drug efficacy and frequent progression of disease. Understanding the characteristics of pre-existing resistant cells is important for evaluating the benefits of first-line combination therapy with second generation inhibitors. However, due to limitations of assay sensitivity, determining the existence and characteristics of resistant cell clones at the start of therapy is difficult. Here we combined a mathematical modeling approach using branching processes with experimental data on the fitness changes (i.e., changes in net reproductive rate) conferred by BCR-ABL kinase domain mutations to investigate the likelihood, composition, and diversity of pre-existing resistance. Furthermore, we studied the impact of these factors on the response to tyrosine kinase inhibitors. Our approach predicts that in most patients, there is at most one resistant clone present at the time of diagnosis of their disease. Interestingly, patients are no more likely to harbor the most aggressive, pan-resistant T315I mutation than any other resistance mutation; however, T315I cells on average establish larger-sized clones at the time of diagnosis. We established that for patients diagnosed late, the relative benefit of combination therapy over monotherapy with imatinib is significant, while this benefit is modest for patients with a typically early diagnosis time. These findings, after pre-clinical validation, will have implications for the clinical management of CML: we recommend that patients with advanced-phase disease be treated with combination therapy with at least two tyrosine kinase inhibitors. PMID:22140458

  11. Toxoplasma gondii calcium-dependent protein kinase 1 is a target for selective kinase inhibitors

    PubMed Central

    Ojo, Kayode K; Larson, Eric T; Keyloun, Katelyn R; Castaneda, Lisa J; DeRocher, Amy E; Inampudi, Krishna K; Kim, Jessica E; Arakaki, Tracy L; Murphy, Ryan C; Zhang, Li; Napuli, Alberto J; Maly, Dustin J; Verlinde, Christophe LMJ; Buckner, Frederick S; Parsons, Marilyn; Hol, Wim GJ; Merritt, Ethan A; Van Voorhis, Wesley C

    2010-01-01

    New drugs are needed to treat toxoplasmosis. Toxoplasma gondii calcium-dependent protein kinases (TgCDPKs) are attractive targets because they are absent in mammals. We show that TgCDPK1 is inhibited by low nanomolar levels of bumped kinase inhibitors (BKIs), compounds designed to be inactive against mammalian kinases. Cocrystal structures of TgCDPK1 with BKIs confirm that the structural basis for selectivity is due to the unique glycine gatekeeper residue in the ATP-binding site at residue 128. We show that BKIs interfere with an early step in T. gondii infection of human cells in culture. Furthermore, we show that TgCDPK1 is the in vivo target of BKIs because T. gondii cells expressing a glycine to methionine gatekeeper mutant enzyme show significantly decreased sensitivity to this class of selective kinase inhibitors. Thus, design of selective TgCDPK1 inhibitors with low host toxicity may be achievable. PMID:20436472

  12. Guanidinium-based derivatives: searching for new kinase inhibitors.

    PubMed

    Diez-Cecilia, Elena; Kelly, Brendan; Perez, Concepcion; Zisterer, Daniela M; Nevin, Daniel K; Lloyd, David G; Rozas, Isabel

    2014-06-23

    Considering the structural similarities between the kinase inhibitor sorafenib and 4,4'-bis-guanidinium derivatives previously prepared by Rozas and co., which display interesting cytotoxicity in cancer cells, we have studied whether this activity could result from kinase inhibition. Five new families have been prepared consisting of unsubstituted and aryl-substituted 3,4'-bis-guanidiniums, 3,4'-bis-2-aminoimidazolinium and 3-acetamide-4'-(4-chloro-3-trifluoromethylphenyl)guanidinium derivatives. Cytotoxicity (measuring the IC50 values) and apoptosis studies in human HL-60 promyelocytic leukemia cells were carried out for these compounds. Additionally, their potential inhibitory effect was explored on a panel of kinases known to be involved in apoptotic pathways. The previously prepared cytotoxic 4,4'-bis-guanidiniums did not inhibit any of these kinases; however, some of the novel 3,4'-substituted derivatives showed a high percentage inhibition of RAF-1/MEK-1, for which the potential mode of binding was evaluated by docking studies. The interesting antitumour properties showed by these compounds open up new exciting lines of investigation for kinase inhibitors as anticancer agents and also highlights the relevance of the guanidinium moiety for protein kinase inhibitors chemical design.

  13. Polo-like kinase inhibitors in hematologic malignancies.

    PubMed

    Talati, Chetasi; Griffiths, Elizabeth A; Wetzler, Meir; Wang, Eunice S

    2016-02-01

    Polo-like kinases (Plk) are key regulators of the cell cycle and multiple aspects of mitosis. Two agents that inhibit the Plk signaling pathway have shown promising activity in patients with hematologic malignancies and are currently in phase III trials. Volasertib is a Plk inhibitor under evaluation combined with low-dose cytarabine in older patients with acute myeloid leukemia (AML) ineligible for intensive induction therapy. Rigosertib, a dual inhibitor of the Plk and phosphatidylinositol 3-kinase pathways, is under investigation in patients with myelodysplastic syndrome (MDS) who have failed azacitidine or decitabine treatment. The prognosis for patients with AML, who are ineligible for intensive induction therapy, and for those with MDS refractory/relapsed after a hypomethylating agent, remains poor. Novel approaches, such as Plk inhibitors, are urgently needed for these patients. Here, we provide a comprehensive overview of the current state of development of Plk inhibitors for the treatment of hematologic malignancies.

  14. Computational Study of the “DFG-Flip” Conformational Transition in c-Abl and c-Src Tyrosine Kinases

    PubMed Central

    2015-01-01

    Protein tyrosine kinases are crucial to cellular signaling pathways regulating cell growth, proliferation, metabolism, differentiation, and migration. To maintain normal regulation of cellular signal transductions, the activities of tyrosine kinases are also highly regulated. The conformation of a three-residue motif Asp-Phe-Gly (DFG) near the N-terminus of the long “activation” loop covering the catalytic site is known to have a critical impact on the activity of c-Abl and c-Src tyrosine kinases. A conformational transition of the DFG motif can switch the enzyme from an active (DFG-in) to an inactive (DFG-out) state. In the present study, the string method with swarms-of-trajectories was used to computationally determine the reaction pathway connecting the two end-states, and umbrella sampling calculations were carried out to characterize the thermodynamic factors affecting the conformations of the DFG motif in c-Abl and c-Src kinases. According to the calculated free energy landscapes, the DFG-out conformation is clearly more favorable in the case of c-Abl than that of c-Src. The calculations also show that the protonation state of the aspartate residue in the DFG motif strongly affects the in/out conformational transition in c-Abl, although it has a much smaller impact in the case of c-Src due to local structural differences. PMID:25548962

  15. A screening-based approach to circumvent tumor microenvironment-driven intrinsic resistance to BCR-ABL+ inhibitors in Ph+ acute lymphoblastic leukemia.

    PubMed

    Singh, Harpreet; Shelat, Anang A; Singh, Amandeep; Boulos, Nidal; Williams, Richard T; Guy, R Kiplin

    2014-01-01

    Signaling by the BCR-ABL fusion kinase drives Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Despite their clinical activity in many patients with CML, the BCR-ABL kinase inhibitors (BCR-ABL-KIs) imatinib, dasatinib, and nilotinib provide only transient leukemia reduction in patients with Ph+ ALL. While host-derived growth factors in the leukemia microenvironment have been invoked to explain this drug resistance, their relative contribution remains uncertain. Using genetically defined murine Ph+ ALL cells, we identified interleukin 7 (IL-7) as the dominant host factor that attenuates response to BCR-ABL-KIs. To identify potential combination drugs that could overcome this IL-7-dependent BCR-ABL-KI-resistant phenotype, we screened a small-molecule library including Food and Drug Administration-approved drugs. Among the validated hits, the well-tolerated antimalarial drug dihydroartemisinin (DHA) displayed potent activity in vitro and modest in vivo monotherapy activity against engineered murine BCR-ABL-KI-resistant Ph+ ALL. Strikingly, cotreatment with DHA and dasatinib in vivo strongly reduced primary leukemia burden and improved long-term survival in a murine model that faithfully captures the BCR-ABL-KI-resistant phenotype of human Ph+ ALL. This cotreatment protocol durably cured 90% of treated animals, suggesting that this cell-based screening approach efficiently identified drugs that could be rapidly moved to human clinical testing.

  16. Ribavirin Inhibits the Activity of mTOR/eIF4E, ERK/Mnk1/eIF4E Signaling Pathway and Synergizes with Tyrosine Kinase Inhibitor Imatinib to Impair Bcr-Abl Mediated Proliferation and Apoptosis in Ph+ Leukemia

    PubMed Central

    Gong, Yuping; Shi, Rui; Yang, Xi; Naren, Duolan; Yan, Tianyou

    2015-01-01

    The eukaryotic translation initiation factor 4E (eIF4E), which is the main composition factor of eIF4F translation initiation complex, influences the growth of tumor through modulating cap-dependent protein translation. Previous studies reported that ribavirin could suppress eIF4E-controlled translation and reduce the synthesis of onco-proteins. Here, we investigated the anti-leukemic effects of ribavirin alone or in combination with tyrosine kinase inhibitor imatinib in Philadelphia chromosome positive (Ph+) leukemia cell lines SUP-B15 (Ph+ acute lymphoblastic leukemia cell line, Ph+ ALL) and K562 (chronic myelogenous leukemia cell line, CML). Our results showed that ribavirin had anti-proliferation effect; it down-regulated the phosphorylation levels of Akt, mTOR, 4EBP1, and eIF4E proteins in the mTOR/eIF4E signaling pathway, and MEK, ERK, Mnk1 and eIF4E proteins in ERK/Mnk1/eIF4E signaling pathway; reduced the expression of Mcl-1 (a translation substrates of eIF4F translation initiation complex) at protein synthesis level not mRNA transcriptional level; and induced cell apoptosis in both SUP-B15 and K562. 7-Methyl-guanosine cap affinity assay further demonstrated that ribavirin remarkably increased the eIF4E binding to 4EBP1 and decreased the combination of eIF4E with eIF4G, consequently resulting in a major inhibition of eIF4F complex assembly. The combination of ribavirin with imatinib enhanced antileukemic effects mentioned above, indicating that two drugs have synergistic anti-leukemic effect. Consistent with the cell lines, similar results were observed in Ph+ acute lymphoblastic primary leukemic blasts; however, the anti-proliferative role of ribavirin in other types of acute primary leukemic blasts was not obvious, which indicated that the anti-leukemic effect of ribavirin was different in cell lineages. PMID:26317515

  17. Screening of kinase inhibitors targeting BRAF for regulating autophagy based on kinase pathways.

    PubMed

    Zhang, Yingmei; Xue, Dongbo; Wang, Xiaochun; Lu, Ming; Gao, Bo; Qiao, Xin

    2014-01-01

    The aim of this study was to identify agents that regulate autophagy. A total of 544 differentially expressed genes were screened from the intersection set of GSE2435 and GSE31040, which was obtained from the Gene Expression Omnibus database and 19 differentially expressed kinases were selected according to a 'protein kinase database'. Gene ontology‑biological process (GO-BP) enrichment analysis revealed that the 19 kinases were mainly associated with phosphorylation. The protein-protein interaction network exhibited 30 differentially expressed genes that interacted with BRAF, and GO-BP enrichment analysis showed the function of these genes were mainly involved in cell death and apoptosis. The kinase-kinase inhibitor regulatory network identified16 kinase inhibitors that specifically inhibited BRAF. Previous studies indicated that sorafenib is capable of regulating autophagy and regorafenib has also been reported; however, there have been no studies regarding the regulation of autophagy by afatinib, selumetinib, PD318088, axitinib, TAK-733, GDC-0980, GSK2126458, PLX-4720, AS703026, trametinib, GDC-0941 and PF-04217903. Thus, these kinase inhibitors are potential targets for further study on the regulation of autophagy in the future.

  18. Cyclin-Dependent Kinase Inhibitors as Anticancer Therapeutics.

    PubMed

    Law, Mary E; Corsino, Patrick E; Narayan, Satya; Law, Brian K

    2015-11-01

    Cyclin-dependent kinases (CDKs) have been considered promising drug targets for a number of years, but most CDK inhibitors have failed rigorous clinical testing. Recent studies demonstrating clear anticancer efficacy and reduced toxicity of CDK4/6 inhibitors such as palbociclib and multi-CDK inhibitors such as dinaciclib have rejuvenated the field. Favorable results with palbociclib and its recent U.S. Food and Drug Administration approval demonstrate that CDK inhibitors with narrow selectivity profiles can have clinical utility for therapy based on individual tumor genetics. A brief overview of results obtained with ATP-competitive inhibitors such as palbociclib and dinaciclib is presented, followed by a compilation of new avenues that have been pursued toward the development of novel, non-ATP-competitive CDK inhibitors. These creative ways to develop CDK inhibitors are presented along with crystal structures of these agents complexed with CDK2 to highlight differences in their binding sites and mechanisms of action. The recent successes of CDK inhibitors in the clinic, combined with the potential for structure-based routes to the development of non-ATP-competitive CDK inhibitors, and evidence that CDK inhibitors may have use in suppressing chromosomal instability and in synthetic lethal drug combinations inspire optimism that CDK inhibitors will become important weapons in the fight against cancer.

  19. The specificities of protein kinase inhibitors: an update.

    PubMed Central

    Bain, Jenny; McLauchlan, Hilary; Elliott, Matthew; Cohen, Philip

    2003-01-01

    We have previously examined the specificities of 28 commercially available compounds, reported to be relatively selective inhibitors of particular serine/threonine-specific protein kinases [Davies, Reddy, Caivano and Cohen (2000) Biochem. J. 351, 95-105]. In the present study, we have extended this analysis to a further 14 compounds. Of these, indirubin-3'-monoxime, SP 600125, KT 5823 and ML-9 were found to inhibit a number of protein kinases and conclusions drawn from their use in cell-based assays are likely to be erroneous. Kenpaullone, Alsterpaullone, Purvalanol, Roscovitine, pyrazolopyrimidine 1 (PP1), PP2 and ML-7 were more specific, but still inhibited two or more protein kinases with similar potency. Our results suggest that the combined use of Roscovitine and Kenpaullone may be useful for identifying substrates and physiological roles of cyclin-dependent protein kinases, whereas the combined use of Kenpaullone and LiCl may be useful for identifying substrates and physiological roles of glycogen synthase kinase 3. The combined use of SU 6656 and either PP1 or PP2 may be useful for identifying substrates of Src family members. Epigallocatechin 3-gallate, one of the main polyphenolic constituents of tea, inhibited two of the 28 protein kinases in the panel, dual-specificity, tyrosine-phosphorylated and regulated kinase 1A (DYRK1A; IC(50)=0.33 microM) and p38-regulated/activated kinase (PRAK; IC(50)=1.0 microM). PMID:12534346

  20. Old Tyrosine Kinase Inhibitors and Newcomers in Gastrointestinal Cancer Treatment.

    PubMed

    Giordani, Erika; Zoratto, Federica; Strudel, Martina; Papa, Anselmo; Rossi, Luigi; Minozzi, Marina; Caruso, Davide; Zaccarelli, Eleonora; Verrico, Monica; Tomao, Silverio

    2016-01-01

    Gastrointestinal cancer treatment is based more on molecular biology that has provided increasing knowledge about cancer pathogenesis on which targeted therapy is being developed. Precisely, targeted therapy is defined as a "type of treatment that uses drugs, such as monoclonal antibodies or tyrosine kinase inhibitors, to identify and attack specific cancer cells". Nowadays, the United States Food and Drug Administration has approved many targeted therapies for gastrointestinal cancer treatment, as many are in various phases of development as well. In a previous review we discussed the main monoclonal antibodies used and studied in gastrointestinal cancer. In addition to monoclonal antibodies, tyrosine kinase inhibitors represent another class of targeted therapy and following the approval of imatinib for gastrointestinal stromal tumours, other tyrosine kinase inhibitors have been approved for gastrointestinal cancers treatment such as sunitinib, regoragenib, sorafenib and erlotinib. Moving forward, the purpose of this review is to focus on the efficacy data of main tyrosine kinase inhibitors commonly used in the personalized treatment of each gastrointestinal tumour and to provide a comprehensive overview about experimental targeted therapies ongoing in this setting.

  1. FDA-approved small-molecule kinase inhibitors.

    PubMed

    Wu, Peng; Nielsen, Thomas E; Clausen, Mads H

    2015-07-01

    Kinases have emerged as one of the most intensively pursued targets in current pharmacological research, especially for cancer, due to their critical roles in cellular signaling. To date, the US FDA has approved 28 small-molecule kinase inhibitors, half of which were approved in the past 3 years. While the clinical data of these approved molecules are widely presented and structure-activity relationship (SAR) has been reported for individual molecules, an updated review that analyzes all approved molecules and summarizes current achievements and trends in the field has yet to be found. Here we present all approved small-molecule kinase inhibitors with an emphasis on binding mechanism and structural features, summarize current challenges, and discuss future directions in this field.

  2. A BCR-ABL Kinase Activity-Independent Signaling Pathway in Chronic Myelogenous Leukemia

    DTIC Science & Technology

    2008-02-01

    myeloproliferative disease in mice receiving P210 bcr/abl-transduced bone marrow. Blood. 1998;92:3780-3792. 17. Zhang X, Ren R. Bcr-Abl efficiently induces a... myeloproliferative disease and production of excess interleukin-3 and granulocyte-macrophage colony-stimulating factor in mice: a novel model for chronic...Xu L, et al. Efficient and rapid induction of a chronic myelogenous leukemia-like myeloproliferative disease in mice receiving P210 bcr/abl-transduced

  3. Clinical development of phosphatidylinositol 3-kinase inhibitors for cancer treatment

    PubMed Central

    2012-01-01

    The phosphatidylinositol 3-kinase (PI3K) pathway is commonly deregulated in cancer. In recent years, the results of the first phase I clinical trials with PI3K inhibitors have become available. In comparison to other targeted agents such v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors in melanoma or crizotinib in anaplastic lymphoma receptor tyrosine kinase (ALK) translocated tumors, the number of objective responses to PI3K inhibitors is less dramatic. In this review we propose possible strategies to optimize the clinical development of PI3K inhibitors: by exploring the potential role of PI3K isoform-specific inhibitors in improving the therapeutic index, molecular characterization as a basis for patient selection, and the relevance of performing serial tumor biopsies to understand the associated mechanisms of drug resistance. The main focus of this review will be on PI3K isoform-specific inhibitors by describing the functions of different PI3K isoforms, the preclinical activity of selective PI3K isoform-specific inhibitors and the early clinical data of these compounds. PMID:23232172

  4. Re-purposing clinical kinase inhibitors to enhance chemosensitivity by overriding checkpoints

    PubMed Central

    Beeharry, Neil; Banina, Eugenia; Hittle, James; Skobeleva, Natalia; Khazak, Vladimir; Deacon, Sean; Andrake, Mark; Egleston, Brian L; Peterson, Jeffrey R; Astsaturov, Igor; Yen, Timothy J

    2014-01-01

    Inhibitors of the DNA damage checkpoint kinase, Chk1, are highly effective as chemo- and radio-sensitizers in preclinical studies but are not well-tolerated by patients. We exploited the promiscuous nature of kinase inhibitors to screen 9 clinically relevant kinase inhibitors for their ability to sensitize pancreatic cancer cells to a sub-lethal concentration of gemcitabine. Bosutinib, dovitinib, and BEZ-235 were identified as sensitizers that abrogated the DNA damage checkpoint. We further characterized bosutinib, an FDA-approved Src/Abl inhibitor approved for chronic myelogenous leukemia. Unbeknownst to us, we used an isomer (Bos-I) that was unknowingly synthesized and sold to the research community as “authentic” bosutinib. In vitro and cell-based assays showed that both the authentic bosutinib and Bos-I inhibited DNA damage checkpoint kinases Chk1 and Wee1, with Bos-I showing greater potency. Imaging data showed that Bos-I forced cells to override gemcitabine-induced DNA damage checkpoint arrest and destabilized stalled replication forks. These inhibitors enhanced sensitivity to the DNA damaging agents’ gemcitabine, cisplatin, and doxorubicin in pancreatic cancer cell lines. The in vivo efficacy of Bos-I was validated using cells derived directly from a pancreatic cancer patient’s tumor. Notably, the xenograft studies showed that the combination of gemcitabine and Bos-I was significantly more effective in suppressing tumor growth than either agent alone. Finally, we show that the gatekeeper residue in Wee1 dictates its sensitivity to the 2 compounds. Our strategy to screen clinically relevant kinase inhibitors for off-target effects on cell cycle checkpoints is a promising approach to re-purpose drugs as chemosensitizers. PMID:24955955

  5. Re-purposing clinical kinase inhibitors to enhance chemosensitivity by overriding checkpoints.

    PubMed

    Beeharry, Neil; Banina, Eugenia; Hittle, James; Skobeleva, Natalia; Khazak, Vladimir; Deacon, Sean; Andrake, Mark; Egleston, Brian L; Peterson, Jeffrey R; Astsaturov, Igor; Yen, Timothy J

    2014-01-01

    Inhibitors of the DNA damage checkpoint kinase, Chk1, are highly effective as chemo- and radio-sensitizers in preclinical studies but are not well-tolerated by patients. We exploited the promiscuous nature of kinase inhibitors to screen 9 clinically relevant kinase inhibitors for their ability to sensitize pancreatic cancer cells to a sub-lethal concentration of gemcitabine. Bosutinib, dovitinib, and BEZ-235 were identified as sensitizers that abrogated the DNA damage checkpoint. We further characterized bosutinib, an FDA-approved Src/Abl inhibitor approved for chronic myelogenous leukemia. Unbeknownst to us, we used an isomer (Bos-I) that was unknowingly synthesized and sold to the research community as "authentic" bosutinib. In vitro and cell-based assays showed that both the authentic bosutinib and Bos-I inhibited DNA damage checkpoint kinases Chk1 and Wee1, with Bos-I showing greater potency. Imaging data showed that Bos-I forced cells to override gemcitabine-induced DNA damage checkpoint arrest and destabilized stalled replication forks. These inhibitors enhanced sensitivity to the DNA damaging agents' gemcitabine, cisplatin, and doxorubicin in pancreatic cancer cell lines. The in vivo efficacy of Bos-I was validated using cells derived directly from a pancreatic cancer patient's tumor. Notably, the xenograft studies showed that the combination of gemcitabine and Bos-I was significantly more effective in suppressing tumor growth than either agent alone. Finally, we show that the gatekeeper residue in Wee1 dictates its sensitivity to the 2 compounds. Our strategy to screen clinically relevant kinase inhibitors for off-target effects on cell cycle checkpoints is a promising approach to re-purpose drugs as chemosensitizers.

  6. Prolonged and tunable residence time using reversible covalent kinase inhibitors

    PubMed Central

    Bradshaw, J. Michael; McFarland, Jesse M.; Paavilainen, Ville O.; Bisconte, Angelina; Tam, Danny; Phan, Vernon T.; Romanov, Sergei; Finkle, David; Shu, Jin; Patel, Vaishali; Ton, Tony; Li, Xiaoyan; Loughhead, David G.; Nunn, Philip A.; Karr, Dane E.; Gerritsen, Mary E.; Funk, Jens Oliver; Owens, Timothy D.; Verner, Erik; Brameld, Ken A.; Hill, Ronald J.; Goldstein, David M.; Taunton, Jack

    2015-01-01

    Drugs with prolonged, on-target residence time often show superior efficacy, yet general strategies for optimizing drug-target residence time are lacking. Here, we demonstrate progress toward this elusive goal by targeting a noncatalytic cysteine in Bruton's tyrosine kinase (BTK) with reversible covalent inhibitors. Utilizing an inverted orientation of the cysteine-reactive cyanoacrylamide electrophile, we identified potent and selective BTK inhibitors that demonstrate biochemical residence times spanning from minutes to 7 days. An inverted cyanoacrylamide with prolonged residence time in vivo remained bound to BTK more than 18 hours after clearance from the circulation. The inverted cyanoacrylamide strategy was further utilized to discover fibroblast growth factor receptor (FGFR) kinase inhibitors with residence times of several days, demonstrating generalizability of the approach. Targeting noncatalytic cysteines with inverted cyanoacrylamides may serve as a broadly applicable platform that facilitates “residence time by design”, the ability to modulate and improve the duration of target engagement in vivo. PMID:26006010

  7. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials

    PubMed Central

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

  8. Resistance to HER2-directed antibodies and tyrosine kinase inhibitors

    PubMed Central

    Garrett, Joan T

    2011-01-01

    The antibody trastuzumab and the tyrosine kinase inhibitor lapatinib are approved by the FDA for the treatment of HER2-overexpressing breast cancer. These anti-HER2 drugs are changing the natural history of HER2-overexpressing breast cancer. However, therapeutic resistance to trastuzumab or lapatinib, as either single-agents or in combination with chemotherapy in the metastatic setting, typically occurs within months of starting therapy. Several mechanisms of trastuzumab-resistance have been reported that include signaling from other HER receptors, signaling from receptor tyrosine kinases (RTKs) outside of the HER (ErbB) family, increased phosphatidylinositol-3-kinase signaling, and the presence of truncated forms of HER2. Mechanisms of resistance to lapatinib also point to increased phosphatidylinositol 3-kinase signaling as well as derepression/activation of compensatory survival pathways. In this review, we discuss how these models and mechanisms enhance our understanding of the clinical resistance to HER2-directed therapies. PMID:21307659

  9. Clinical experience with aurora kinase inhibitors: a review.

    PubMed

    Boss, David S; Beijnen, Jos H; Schellens, Jan H M

    2009-08-01

    The aurora kinase family of serine/threonine kinases comprises three members, designated auroras A, B, and C. Auroras A and B are essential components of the mitotic pathway, ensuring proper chromosome assembly, formation of the mitotic spindle, and cytokinesis. The role of aurora C is less clear. Overexpression of aurora A and B has been observed in several tumor types, and has been linked with a poor prognosis of cancer patients. Several small molecules targeting aurora kinases A and B or both have been evaluated preclinically and in early phase I trials. In this review we aim to summarize the most recent advances in the development of aurora kinase inhibitors, with a focus on the clinical data.

  10. Inhibitors of glycogen synthase 3 kinase

    DOEpatents

    Schultz, Peter; Ring, David B.; Harrison, Stephen D.; Bray, Andrew M.

    2006-05-30

    Compounds of formula 1: ##STR00001## wherein R.sub.1 is alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, or heteroaralkyl, substituted with 0 3 substituents selected from lower alkyl, halo, hydroxy, lower alkoxy, amino, lower alkyl-amino, and nitro; R.sub.2 is hydroxy, amino, or lower alkoxy; R.sub.3 is H, lower alkyl, lower acyl, lower alkoxy-acyl, or amino-acyl; R.sub.4 is H or lower alkyl; and pharmaceutically acceptable salts and esters thereof; are effective inhibitors of GSK3.

  11. Inhibitors of glycogen synthase 3 kinase

    DOEpatents

    Schultz, Peter; Ring, David B.; Harrison, Stephen D.; Bray, Andrew M.

    2000-01-01

    Compounds of formula 1: ##STR1## wherein R.sub.1 is alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, or heteroaralkyl, substituted with 0-3 substituents selected from lower alkyl, halo, hydroxy, lower alkoxy, amino, lower alkyl-amino, and nitro; R.sub.2 is hydroxy, amino, or lower alkoxy; R.sub.3 is H, lower alkyl, lower acyl, lower alkoxy-acyl, or amnino-acyl; R.sub.4 is H or lower alkyl; and pharmaceutically acceptable salts and esters thereof; are effective inhibitors of GSK3.

  12. Identification of common inhibitors of wild-type and T315I mutant of BCR-ABL through the parallel structure-based virtual screening

    NASA Astrophysics Data System (ADS)

    Park, Hwangseo; Hong, Seunghee; Hong, Sungwoo

    2012-08-01

    Although the constitutively activated break-point cluster region-Abelson (BCR-ABL) tyrosine kinase was well known to be responsible for chronic myelogenous leukemia (CML), the existence of drug-resistant mutants of BCR-ABL has made it difficult to develop effective anti-CML drugs. Here, we report the first example for a successful application of the structure-based virtual screening to identify two common inhibitors equipotent for the wild type and the most drug-resistant T315I mutant of BCR-ABL. Because both inhibitors were screened for having desirable physicochemical properties as a drug candidate and revealed micromolar inhibitory activities, they deserve consideration for further development by structure-activity relationship (SAR) studies to optimize the anti-CML activity. We also address the structural features relevant to the stabilizations of the identified inhibitors in the ATP-binding sites. The results indicate that the inhibitors should be less stabilized by the hydrogen-bond interactions with the change of the receptor from the wild type to T315I mutant due to the replacement of the hydroxy group with the ethyl moiety in the ATP-binding site. Nonetheless, the inhibitors are found to be capable of maintaining the potency for the mutant through the strengthening of hydrophobic interactions to the extent sufficient to compensate for the loss of some hydrogen bonds. This differential binding mode may serve as key information for designing new common inhibitors of the wild type and T315I mutant of BCR-ABL.

  13. Discovery and characterization of a novel potent type II native and mutant BCR-ABL inhibitor (CHMFL-074) for Chronic Myeloid Leukemia (CML).

    PubMed

    Liu, Feiyang; Wang, Beilei; Wang, Qiang; Qi, Ziping; Chen, Cheng; Kong, Lu-Lu; Chen, Ji-Yun; Liu, Xiaochuan; Wang, Aoli; Hu, Chen; Wang, Wenchao; Wang, Huiping; Wu, Fan; Ruan, Yanjie; Qi, Shuang; Liu, Juan; Zou, Fengming; Hu, Zhenquan; Wang, Wei; Wang, Li; Zhang, Shanchun; Yun, Cai-Hong; Zhai, Zhimin; Liu, Jing; Liu, Qingsong

    2016-07-19

    BCR gene fused ABL kinase is the critical driving force for the Philadelphia Chromosome positive (Ph+) Chronic Myeloid Leukemia (CML) and has been extensively explored as a drug target. With a structure-based drug design approach we have discovered a novel inhibitor CHMFL-074, that potently inhibits both the native and a variety of clinically emerged mutants of BCR-ABL kinase. The X-ray crystal structure of CHMFL-074 in complex with ABL1 kinase (PDB ID: 5HU9) revealed a typical type II binding mode (DFG-out) but relatively rare hinge binding. Kinome wide selectivity profiling demonstrated that CHMFL-074 bore a high selectivity (S score(1) = 0.03) and potently inhibited ABL1 kinase (IC50: 24 nM) and PDGFR α/β (IC50: 71 nM and 88 nM). CHMFL-074 displayed strong anti-proliferative efficacy against BCR-ABL-driven CML cell lines such as K562 (GI50: 56 nM), MEG-01 (GI50: 18 nM) and KU812 (GI50: 57 nM). CHMFL-074 arrested cell cycle into the G0/G1 phase and induced apoptosis in the Ph+ CML cell lines. In addition, it potently inhibited the CML patient primary cell's proliferation but did not affect the normal bone marrow cells. In the CML cell K562 inoculated xenograft mouse model, oral administration of 100 mg/kg/d of CHMFL-074 achieved a tumor growth inhibition (TGI) of 65% without exhibiting apparent toxicity. As a potential drug candidate for fighting CML, CHMFL-074 is under extensive preclinical safety evaluation now.

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

    SciTech Connect

    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.

    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

  15. Molecular modeling studies of phenoxypyrimidinyl imidazoles as p38 kinase inhibitors using QSAR and docking.

    PubMed

    Ravindra, G K; Achaiah, G; Sastry, G N

    2008-04-01

    p38 Kinase plays a vital role in inflammation mediated by tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) pathways and inhibitors of p38 kinase provide effective approach for the treatment of inflammatory diseases. Pyridinyl and pyrimidinyl imidazoles, selectively inhibit p38alpha MAP kinase, are useful in the treatment of inflammatory diseases like rheumatoid arthritis. Three dimensional quantitative structure-activity relationship studies (3D-QSAR) involving comparative molecular field analysis (CoMFA) and comparative similarity indices analysis (CoMSIA) and molecular docking were performed on 44 phenoxypyrimidinyl imidazole p38 kinase inhibitors to find out the structural relationship with the activity. The best predictive CoMFA model with atom fit alignment resulted in cross-validated r(2) value of 0.553, noncross-validated r(2) value of 0.908 and standard error of estimate 0.187. Similarly the best predictive CoMSIA model was derived with q(2) of 0.508, noncross-validated r(2) of 0.894 and standard error of estimate of 0.197, comprising steric, electrostatic, hydrophobic and hydrogen bond donor fields. These models were able to predict the activity of test set molecules efficiently within an acceptable error range. GOLD and FlexX were employed to dock the inhibitors into the active site of the p38 kinase and these docking studies revealed the vital interactions and binding conformation of the inhibitors. The information rendered by 3D-QSAR models and the docking interactions may afford valuable clues to optimize the lead and design new potential inhibitors.

  16. Ligand-protein interactions of selective casein kinaseinhibitors.

    PubMed

    Mente, Scot; Arnold, Eric; Butler, Todd; Chakrapani, Subramanyam; Chandrasekaran, Ramalakshmi; Cherry, Kevin; DiRico, Ken; Doran, Angela; Fisher, Katherine; Galatsis, Paul; Green, Michael; Hayward, Matthew; Humphrey, John; Knafels, John; Li, Jianke; Liu, Shenping; Marconi, Michael; McDonald, Scott; Ohren, Jeff; Paradis, Vanessa; Sneed, Blossom; Walton, Kevin; Wager, Travis

    2013-09-12

    Casein kinase 1δ (CK1δ) and 1ε (CK1ε) are believed to be necessary enzymes for the regulation of circadian rhythms in all mammals. On the basis of our previously published work demonstrating a CK1ε-preferring compound to be an ineffective circadian clock modulator, we have synthesized a series of pyrazole-substitued pyridine inhibitors, selective for the CK1δ isoform. Additionally, using structure-based drug design, we have been able to exploit differences in the hinge region between CK1δ and p38 to find selective inhibitors that have minimal p38 activity. The SAR, brain exposure, and the effect of these inhibitors on mouse circadian rhythms are described. The in vivo evaluation of these inhibitors demonstrates that selective inhibition of CK1δ at sufficient central exposure levels is capable of modulating circadian rhythms.

  17. Structure-guided discovery of cyclin-dependent kinase inhibitors

    SciTech Connect

    Fischmann, Thierry O.; Hruza, Alan; Duca, Jose S.; Ramanathan, Lata; Mayhood, Todd; Windsor, William T.; Le, Hung V.; Guzi, Timothy J.; Dwyer, Michael P.; Paruch, Kamil; Doll, Ronald J.; Lees, Emma; Parry, David; Seghezzi, Wolfgang; Madison, Vincent

    2008-10-02

    CDK2 inhibitors containing the related bicyclic heterocycles pyrazolopyrimidines and imidazopyrazines were discovered through high-throughput screening. Crystal structures of inhibitors with these bicyclic cores and two more related ones show that all but one have a common binding mode featuring two hydrogen bonds (H-bonds) to the backbone of the kinase hinge region. Even though ab initio computations indicated that the imidazopyrazine core would bind more tightly to the hinge, pyrazolopyrimidines gain an advantage in potency through participation of N4 in an H-bond network involving two catalytic residues and bridging water molecules. Further insight into inhibitor/CDK2 interactions was gained from analysis of additional crystal structures. Significant gains in potency were obtained by optimizing the fit of hydrophobic substituents to the gatekeeper region of the ATP binding site. The most potent inhibitors have good selectivity.

  18. Comprehensive kinase profile of pacritinib, a nonmyelosuppressive Janus kinase 2 inhibitor

    PubMed Central

    Singer, Jack W; Al-Fayoumi, Suliman; Ma, Haiching; Komrokji, Rami S; Mesa, Ruben; Verstovsek, Srdan

    2016-01-01

    Pacritinib, potent inhibitor of Janus kinase 2 (JAK2), JAK2V617F, and fms-like receptor tyrosine kinase 3, is in Phase III development in myelofibrosis. Among type 1 inhibitors, pacritinib shows a lack of myelosuppression at doses that both inhibit JAK2/signal transducer and activator of transcription 3 pathway and demonstrate clinical efficacy. To elucidate these mechanisms and identify other disease targets, a kinome analysis screened 439 recombinant kinases at 100 nM pacritinib concentration. For kinases with >50% inhibition, pacritinib was titrated from 1 to 100 nM. JAK2, JAK2V617F, FLT3, colony-stimulating factor 1 receptor, and interleukin-1 receptor-associated kinase 1 achieved half-maximal inhibitory concentrations <50 nM. Pacritinib did not inhibit JAK1 (82% control at 100 nM). Lack of myelosuppression may stem from inhibiting JAK2 without affecting JAK1 and reducing hematopoietic inhibitory cytokines by suppressing interleukin-1 receptor-associated kinase 1 or colony-stimulating factor 1 receptor. The pacritinib kinome suggests therapeutic utility in acute myeloid leukemia, myelodysplastic syndrome, chronic myelomonocytic leukemia, solid tumors, and inflammatory conditions. PMID:27574472

  19. SAR156497, an exquisitely selective inhibitor of aurora kinases.

    PubMed

    Carry, Jean-Christophe; Clerc, François; Minoux, Hervé; Schio, Laurent; Mauger, Jacques; Nair, Anil; Parmantier, Eric; Le Moigne, Ronan; Delorme, Cécile; Nicolas, Jean-Paul; Krick, Alain; Abécassis, Pierre-Yves; Crocq-Stuerga, Véronique; Pouzieux, Stéphanie; Delarbre, Laure; Maignan, Sébastien; Bertrand, Thomas; Bjergarde, Kirsten; Ma, Nina; Lachaud, Sylvette; Guizani, Houlfa; Lebel, Rémi; Doerflinger, Gilles; Monget, Sylvie; Perron, Sébastien; Gasse, Francis; Angouillant-Boniface, Odile; Filoche-Rommé, Bruno; Murer, Michel; Gontier, Sylvie; Prévost, Céline; Monteiro, Marie-Line; Combeau, Cécile

    2015-01-08

    The Aurora family of serine/threonine kinases is essential for mitosis. Their crucial role in cell cycle regulation and aberrant expression in a broad range of malignancies have been demonstrated and have prompted intensive search for small molecule Aurora inhibitors. Indeed, over 10 of them have reached the clinic as potential anticancer therapies. We report herein the discovery and optimization of a novel series of tricyclic molecules that has led to SAR156497, an exquisitely selective Aurora A, B, and C inhibitor with in vitro and in vivo efficacy. We also provide insights into its mode of binding to its target proteins, which could explain its selectivity.

  20. Practical synthesis of a p38 MAP kinase inhibitor.

    PubMed

    Achmatowicz, Michał; Thiel, Oliver R; Wheeler, Philip; Bernard, Charles; Huang, Jinkun; Larsen, Robert D; Faul, Margaret M

    2009-01-16

    p38 MAP kinase inhibitors have attracted considerable interest as potential agents for the treatment of inflammatory diseases. Herein, we describe a concise and efficient synthesis of inhibitor 1 that is based on a phthalazine scaffold. Highlights of our approach include a practical synthesis of a 1,6-disubstituted phthalazine building block 24 as well as the one-pot formation of boronic acid 27. Significant synthetic work to understand the reactivity principles of the intermediates helped in selection of the final synthetic route. Subsequent optimization of the individual steps of the final sequence led to a practical synthesis of 1.

  1. Discovery and characterization of a novel potent type II native and mutant BCR-ABL inhibitor (CHMFL-074) for Chronic Myeloid Leukemia (CML)

    PubMed Central

    Chen, Ji-Yun; Liu, Xiaochuan; Wang, Aoli; Hu, Chen; Wang, Wenchao; Wang, Huiping; Wu, Fan; Ruan, Yanjie; Qi, Shuang; Liu, Juan; Zou, Fengming; Hu, Zhenquan; Wang, Wei; Wang, Li; Zhang, Shanchun; Yun, Cai-Hong; Zhai, Zhimin; Liu, Jing; Liu, Qingsong

    2016-01-01

    BCR gene fused ABL kinase is the critical driving force for the Philadelphia Chromosome positive (Ph+) Chronic Myeloid Leukemia (CML) and has been extensively explored as a drug target. With a structure-based drug design approach we have discovered a novel inhibitor CHMFL-074, that potently inhibits both the native and a variety of clinically emerged mutants of BCR-ABL kinase. The X-ray crystal structure of CHMFL-074 in complex with ABL1 kinase (PDB ID: 5HU9) revealed a typical type II binding mode (DFG-out) but relatively rare hinge binding. Kinome wide selectivity profiling demonstrated that CHMFL-074 bore a high selectivity (S score(1) = 0.03) and potently inhibited ABL1 kinase (IC50: 24 nM) and PDGFR α/β (IC50: 71 nM and 88 nM). CHMFL-074 displayed strong anti-proliferative efficacy against BCR-ABL–driven CML cell lines such as K562 (GI50: 56 nM), MEG-01 (GI50: 18 nM) and KU812 (GI50: 57 nM). CHMFL-074 arrested cell cycle into the G0/G1 phase and induced apoptosis in the Ph+ CML cell lines. In addition, it potently inhibited the CML patient primary cell's proliferation but did not affect the normal bone marrow cells. In the CML cell K562 inoculated xenograft mouse model, oral administration of 100 mg/kg/d of CHMFL-074 achieved a tumor growth inhibition (TGI) of 65% without exhibiting apparent toxicity. As a potential drug candidate for fighting CML, CHMFL-074 is under extensive preclinical safety evaluation now. PMID:27322145

  2. Phosphatidylinositol 3-kinase (PI3K) inhibitors as cancer therapeutics

    PubMed Central

    2013-01-01

    Phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate diverse cellular processes including proliferation, adhesion, survival, and motility. Dysregulated PI3K pathway signaling occurs in one-third of human tumors. Aberrantly activated PI3K signaling also confers sensitivity and resistance to conventional therapies. PI3K has been recognized as an attractive molecular target for novel anti-cancer molecules. In the last few years, several classes of potent and selective small molecule PI3K inhibitors have been developed, and at least fifteen compounds have progressed into clinical trials as new anticancer drugs. Among these, idelalisib has advanced to phase III trials in patients with advanced indolent non-Hodgkin’s lymphoma and mantle cell lymphoma. In this review, we summarized the major molecules of PI3K signaling pathway, and discussed the preclinical models and clinical trials of potent small-molecule PI3K inhibitors. PMID:24261963

  3. Targeting Angiogenesis in Colorectal Cancer: Tyrosine Kinase Inhibitors.

    PubMed

    Kircher, Sheetal Mehta; Nimeiri, Halla S; Benson, Al B

    2016-01-01

    Colorectal cancer is commonly diagnosed throughout the world, and treatment options have greatly expanded over the last 2 decades. Targeting angiogenesis has been a major focus of study in a variety of malignancy types. Targeting angiogenesis has been achieved by several mechanisms in colorectal cancer, including use of antiangiogenic small molecule tyrosine kinase inhibitors (TKIs). There have been many attempts and failures to prove efficacy of TKIs in the treatment of colorectal cancer including sorafenib, sunitinib, vatalanib, and tivozanib. Regorafenib was the first TKI to demonstrate efficacy and is an orally active inhibitor of angiogenic (including the vascular endothelial growth factor receptors 1, 2, and 3), stromal, and oncogenic receptor tyrosine kinases. There are ongoing investigations of both regorafenib and ninetanib; however, there remains a critical need to better understand novel combinations with TKIs that could prove more efficacious than available options.

  4. Endocrine side effects of broad-acting kinase inhibitors.

    PubMed

    Lodish, Maya B; Stratakis, Constantine A

    2010-09-01

    Targeted therapy in oncology consists of drugs that specifically interfere with abnormal signaling pathways that are dysregulated in cancer cells. Tyrosine kinase inhibitors (TKIs) take advantage of unique oncogenes that are activated in certain types of cancer, and also target common mechanisms of growth, invasion, metastasis, and angiogenesis. However, many kinase inhibitors for cancer therapy are somewhat nonselective, and most have additional mechanisms of action at the cellular level, which are not completely understood. The use of these agents has increased our knowledge of important side effects, of which the practicing clinician must be aware. Recently, proposed endocrine-related side effects of these agents include alterations in thyroid function, bone metabolism, linear growth, gonadal function, fetal development, and glucose metabolism, and adrenal function. This review summarizes the most recent data on the endocrine side effects of TKIs.

  5. Testing the promiscuity of commercial kinase inhibitors against the AGC kinase group using a split-luciferase screen.

    PubMed

    Jester, Benjamin W; Gaj, Alicia; Shomin, Carolyn D; Cox, Kurt J; Ghosh, Indraneel

    2012-02-23

    Using a newly developed competitive binding assay dependent upon the reassembly of a split reporter protein, we have tested the promiscuity of a panel of reported kinase inhibitors against the AGC group. Many non-AGC targeted kinase inhibitors target multiple members of the AGC group. In general, structurally similar inhibitors consistently exhibited activity toward the same target as well as toward closely related kinases. The inhibition data was analyzed to test the predictive value of either using identity scores derived from residues within 6 Å of the active site or identity scores derived from the entire kinase domain. The results suggest that the active site identity in certain cases may be a stronger predictor of inhibitor promiscuity. The overall results provide general guidelines for establishing inhibitor selectivity as well as for the future design of inhibitors that either target or avoid AGC kinases.

  6. FMS Kinase Inhibitors: Current Status and Future Prospects.

    PubMed

    El-Gamal, Mohammed I; Anbar, Hanan S; Yoo, Kyung Ho; Oh, Chang-Hyun

    2013-05-01

    FMS, first discovered as the oncogene responsible for Feline McDonough Sarcoma, is a type III receptor tyrosine kinase that binds to the macrophage or monocyte colony-stimulating factor (M-CSF or CSF-1). Signal transduction through that binding results in survival, proliferation, and differentiation of monocyte/macrophage lineage. Overexpression of CSF-1 and/or FMS has been implicated in a number of disease states such as the growth of metastasis of certain types of cancer, in promoting osteoclast proliferation in bone osteolysis, and many inflammatory disorders. Inhibition of CSF-1 and/or FMS may help treat these pathological conditions. This article reviews FMS gene, FMS kinase, CSF-1, IL-34, and their roles in bone osteolysis, cancer biology, and inflammation. Monoclonal antibodies, FMS crystal structure, and small molecule FMS kinase inhibitors of different chemical scaffolds are also reviewed.

  7. Discovery of indazoles as inhibitors of Tpl2 kinase.

    PubMed

    Hu, Yonghan; Cole, Derek; Denny, Rajiah Aldrin; Anderson, David R; Ipek, Manus; Ni, Yike; Wang, Xiaolun; Thaisrivongs, Suvit; Chamberlain, Timothy; Hall, J Perry; Liu, Julie; Luong, Michael; Lin, Lih-Ling; Telliez, Jean-Baptiste; Gopalsamy, Ariamala

    2011-08-15

    Synthesis, modeling and structure-activity relationship of indazoles as inhibitors of Tpl2 kinase are described. From a high throughput screening effort, we identified an indazole hit compound 5 that has a single digit micromolar Tpl2 activity. Through SAR modifications at the C3 and C5 positions of the indazole, we discovered compound 31 with good potency in LANCE assay and cell-based p-Erk assay.

  8. A BCR-ABL Kinase Activity-Independent Signaling Pathway in Chronic Myelogenous Leukemia

    DTIC Science & Technology

    2007-02-01

    leukemia (CML), but does not cure mice with BCR-ABL-induced acute lymphoblastic leukemia (ALL), similar to CML lymphoid blast crisis. The inability... leukemia or Ph-positive acute lymphoblastic leukemia who develop imatinib (STI571) resistance. Blood. 2002;99:3472-3475. 9. von Bubnoff N, Schneller F...the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome. N Engl J Med. 2001;344:1038-1042. 11

  9. Phosphoinositide 3-kinase inhibitors induce DNA damage through nucleoside depletion

    PubMed Central

    Juvekar, Ashish; Hu, Hai; Yadegarynia, Sina; Lyssiotis, Costas A.; Ullas, Soumya; Lien, Evan C.; Bellinger, Gary; Son, Jaekyoung; Hok, Rosanna C.; Seth, Pankaj; Daly, Michele B.; Kim, Baek; Scully, Ralph; Asara, John M.; Cantley, Lewis C.; Wulf, Gerburg M.

    2016-01-01

    We previously reported that combining a phosphoinositide 3-kinase (PI3K) inhibitor with a poly-ADP Rib polymerase (PARP)-inhibitor enhanced DNA damage and cell death in breast cancers that have genetic aberrations in BRCA1 and TP53. Here, we show that enhanced DNA damage induced by PI3K inhibitors in this mutational background is a consequence of impaired production of nucleotides needed for DNA synthesis and DNA repair. Inhibition of PI3K causes a reduction in all four nucleotide triphosphates, whereas inhibition of the protein kinase AKT is less effective than inhibition of PI3K in suppressing nucleotide synthesis and inducing DNA damage. Carbon flux studies reveal that PI3K inhibition disproportionately affects the nonoxidative pentose phosphate pathway that delivers Rib-5-phosphate required for base ribosylation. In vivo in a mouse model of BRCA1-linked triple-negative breast cancer (K14-Cre BRCA1f/fp53f/f), the PI3K inhibitor BKM120 led to a precipitous drop in DNA synthesis within 8 h of drug treatment, whereas DNA synthesis in normal tissues was less affected. In this mouse model, combined PI3K and PARP inhibition was superior to either agent alone to induce durable remissions of established tumors. PMID:27402769

  10. Bruton's tyrosine kinase (BTK) inhibitors in clinical trials.

    PubMed

    Burger, Jan A

    2014-03-01

    BTK is a cytoplasmic, non-receptor tyrosine kinase that transmits signals from a variety of cell-surface molecules, including the B-cell receptor (BCR) and tissue homing receptors. Genetic BTK deletion causes B-cell immunodeficiency in humans and mice, making this kinase an attractive therapeutic target for B-cell disorders. The BTK inhibitor ibrutinib (PCI-32765, brand name: Imbruvica) demonstrated high clinical activity in B-cell malignancies, especially in patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenstrom's macroglobulinemia (WM). Therefore, ibrutinib was granted a 'breakthrough therapy' designation for these indications and was recently approved for the treatment of relapsed MCL by the U.S. Food and Drug Administration. Other BTK inhibitors in earlier clinical development include CC-292 (AVL-292), and ONO-4059. In CLL and MCL, ibrutinib characteristically induces redistribution of malignant B cells from tissue sites into the peripheral blood, along with rapid resolution of enlarged lymph nodes and a surge in lymphocytosis. With continuous ibrutinib therapy, growth- and survival-inhibitory activities of ibrutinib result in the normalization of lymphocyte counts and remissions in a majority of patients. This review discusses the clinical advances with BTK inhibitor therapy, as well as its pathophysiological basis, and outlines perspectives for future use of BTK inhibitors.

  11. Synergistic effects of selective inhibitors targeting the PI3K/AKT/mTOR pathway or NUP214-ABL1 fusion protein in human Acute Lymphoblastic Leukemia

    PubMed Central

    Martelli, Alberto M.; Zauli, Giorgio; Milani, Daniela; McCubrey, James A.; Capitani, Silvano; Neri, Luca M.

    2016-01-01

    Philadelphia chromosome-positive (Ph+) Acute Lymphoblastic Leukemia (ALL) accounts for 25–30% of adult ALL and its incidence increases with age in adults >40 years old. Irrespective of age, the ABL1 fusion genes are markers of poor prognosis and amplification of the NUP214-ABL1 oncogene can be detected mainly in patients with T-ALL. T cell malignancies harboring the ABL1 fusion genes are sensitive to many cytotoxic agents, but up to date complete remissions have not been achieved. The PI3K/Akt/mTOR signaling pathway is often activated in leukemias and plays a crucial role in leukemogenesis. We analyzed the effects of three BCR-ABL1 tyrosine kinase inhibitors (TKIs), alone and in combination with a panel of selective PI3K/Akt/mTOR inhibitors, on three NUP214-ABL1 positive T-ALL cell lines that also displayed PI3K/Akt/mTOR activation. Cells were sensitive to anti BCR-ABL1 TKIs Imatinib, Nilotinib and GZD824, that specifically targeted the ABL1 fusion protein, but not the PI3K/Akt/mTOR axis. Four drugs against the PI3K/Akt/mTOR cascade, GSK690693, NVP-BGT226, ZSTK474 and Torin-2, showed marked cytotoxic effects on T-leukemic cells, without affecting the NUP214-ABL1 kinase and related pathway. Dephosphorylation of pAkt and pS6 showed the cytotoxicity of these compounds. Either single or combined administration of drugs against the different targets displayed inhibition of cellular viability associated with a concentration-dependent induction of apoptosis, cell cycle arrest in G0/G1 phase and autophagy, having the combined treatments a significant synergistic cytotoxic effect. Co-targeting NUP214-ABL1 fusion gene and PI3K/Akt/mTOR signaling pathway could represent a new and effective pharmacological strategy to improve the outcome in NUP214-ABL1 positive T-ALL. PMID:27821800

  12. A Fluorescence-Based Thermal Shift Assay Identifies Inhibitors of Mitogen Activated Protein Kinase Kinase 4

    PubMed Central

    Krishna, Sankar N.; Luan, Chi-Hao; Mishra, Rama K.; Xu, Li; Scheidt, Karl A.; Anderson, Wayne F.; Bergan, Raymond C.

    2013-01-01

    Prostate cancer (PCa) is the second highest cause of cancer death in United States males. If the metastatic movement of PCa cells could be inhibited, then mortality from PCa could be greatly reduced. Mitogen-activated protein kinase kinase 4 (MAP2K4) has previously been shown to activate pro-invasion signaling pathways in human PCa. Recognizing that MAP2K4 represents a novel and validated therapeutic target, we sought to develop and characterize an efficient process for the identification of small molecules that target MAP2K4. Using a fluorescence-based thermal shift assay (FTS) assay, we first evaluated an 80 compound library of known kinase inhibitors, thereby identifying 8 hits that thermally stabilized MAP2K4 in a concentration dependent manner. We then developed an in vitro MAP2K4 kinase assay employing the biologically relevant downstream substrates, JNK1 and p38 MAPK, to evaluate kinase inhibitory function. In this manner, we validated the performance of our initial FTS screen. We next applied this approach to a 2000 compound chemically diverse library, identified 7 hits, and confirmed them in the in vitro kinase assay. Finally, by coupling our structure-activity relationship data to MAP2K4's crystal structure, we constructed a model for ligand binding. It predicts binding of our identified inhibitory compounds to the ATP binding pocket. Herein we report the creation of a robust inhibitor-screening platform with the ability to inform the discovery and design of new and potent MAP2K4 inhibitors. PMID:24339940

  13. Pharmacological cyclin dependent kinase inhibitors: Implications for colorectal cancer.

    PubMed

    Balakrishnan, Archana; Vyas, Arpita; Deshpande, Kaivalya; Vyas, Dinesh

    2016-02-21

    Colorectal cancer accounts for a significant proportion of cancer deaths worldwide. The need to develop more chemotherapeutic agents to combat this disease is critical. Cyclin dependent kinases (CDKs), along with its binding partner cyclins, serve to control the growth of cells through the cell cycle. A new class of drugs, termed CDK inhibitors, has been studied in preclinical and now clinical trials. These inhibitors are believed to act as an anti-cancer drug by blocking CDKs to block the uncontrolled cellular proliferation that is hallmark of cancers like colorectal cancer. CDK article provides overview of the emerging drug class of CDK inhibitors and provides a list of ones that are currently in clinical trials.

  14. Monoubiquitinated Fanconi anemia D2 (FANCD2-Ub) is required for BCR-ABL1 kinase-induced leukemogenesis.

    PubMed

    Koptyra, M; Stoklosa, T; Hoser, G; Glodkowska-Mrowka, E; Seferynska, I; Klejman, A; Blasiak, J; Skorski, T

    2011-08-01

    Fanconi D2 (FANCD2) is monoubiquitinated on K561 (FANCD2-Ub) in response to DNA double-strand breaks (DSBs) to stimulate repair of these potentially lethal DNA lesions. FANCD2-Ub was upregulated in CD34+ chronic myeloid leukemia (CML) cells and in BCR-ABL1 kinase-positive cell lines in response to elevated levels of reactive oxygen species (ROS) and DNA cross-linking agent mitomycin C. Downregulation of FANCD2 and inhibition of FANCD2-Ub reduced the clonogenic potential of CD34+ CML cells and delayed BCR-ABL1 leukemogenesis in mice. Retarded proliferation of BCR-ABL1 positive FANCD2-/- leukemia cells could be rescued by FANCD2 expression. BCR-ABL1 positive FANCD2-/- cells accumulated more ROS-induced DSBs in comparison with BCR-ABL1 positive FANCD2+/+ cells. Antioxidants diminished the number of DSBs and enhanced proliferation of BCR-ABL1 positive FANCD2-/- cells. Expression of wild-type FANCD2 and FANCD2(S222A) phosphorylation-defective mutant (deficient in stimulation of intra-S phase checkpoint, but proficient in DSB repair), but not FANCD2(K561R) monoubiquitination-defective mutant (proficient in stimulation of intra-S phase checkpoint, but deficient in DSB repair) reduced the number of DSBs and facilitated proliferation of BCR-ABL1 positive FANCD2-/- cells. We hypothesize that FANCD2-Ub has an important role in BCR-ABL1 leukemogenesis because of its ability to facilitate the repair of numerous ROS-induced DSBs.

  15. A Cell Biologist's Field Guide to Aurora Kinase Inhibitors.

    PubMed

    de Groot, Christian O; Hsia, Judy E; Anzola, John V; Motamedi, Amir; Yoon, Michelle; Wong, Yao Liang; Jenkins, David; Lee, Hyun J; Martinez, Mallory B; Davis, Robert L; Gahman, Timothy C; Desai, Arshad; Shiau, Andrew K

    2015-01-01

    Aurora kinases are essential for cell division and are frequently misregulated in human cancers. Based on their potential as cancer therapeutics, a plethora of small molecule Aurora kinase inhibitors have been developed, with a subset having been adopted as tools in cell biology. Here, we fill a gap in the characterization of Aurora kinase inhibitors by using biochemical and cell-based assays to systematically profile a panel of 10 commercially available compounds with reported selectivity for Aurora A (MLN8054, MLN8237, MK-5108, MK-8745, Genentech Aurora Inhibitor 1), Aurora B (Hesperadin, ZM447439, AZD1152-HQPA, GSK1070916), or Aurora A/B (VX-680). We quantify the in vitro effect of each inhibitor on the activity of Aurora A alone, as well as Aurora A and Aurora B bound to fragments of their activators, TPX2 and INCENP, respectively. We also report kinome profiling results for a subset of these compounds to highlight potential off-target effects. In a cellular context, we demonstrate that immunofluorescence-based detection of LATS2 and histone H3 phospho-epitopes provides a facile and reliable means to assess potency and specificity of Aurora A versus Aurora B inhibition, and that G2 duration measured in a live imaging assay is a specific readout of Aurora A activity. Our analysis also highlights variation between HeLa, U2OS, and hTERT-RPE1 cells that impacts selective Aurora A inhibition. For Aurora B, all four tested compounds exhibit excellent selectivity and do not significantly inhibit Aurora A at effective doses. For Aurora A, MK-5108 and MK-8745 are significantly more selective than the commonly used inhibitors MLN8054 and MLN8237. A crystal structure of an Aurora A/MK-5108 complex that we determined suggests the chemical basis for this higher specificity. Taken together, our quantitative biochemical and cell-based analyses indicate that AZD1152-HQPA and MK-8745 are the best current tools for selectively inhibiting Aurora B and Aurora A, respectively

  16. PP2A Inhibitor PME-1 Drives Kinase Inhibitor Resistance in Glioma Cells.

    PubMed

    Kaur, Amanpreet; Denisova, Oxana V; Qiao, Xi; Jumppanen, Mikael; Peuhu, Emilia; Ahmed, Shafiq U; Raheem, Olayinka; Haapasalo, Hannu; Eriksson, John; Chalmers, Anthony J; Laakkonen, Pirjo; Westermarck, Jukka

    2016-12-01

    Glioblastoma multiforme lacks effective therapy options. Although deregulated kinase pathways are drivers of malignant progression in glioblastoma multiforme, glioma cells exhibit intrinsic resistance toward many kinase inhibitors, and the molecular basis of this resistance remains poorly understood. Here, we show that overexpression of the protein phosphatase 2A (PP2A) inhibitor protein PME-1 drives resistance of glioma cells to various multikinase inhibitors. The PME-1-elicited resistance was dependent on specific PP2A complexes and was mediated by a decrease in cytoplasmic HDAC4 activity. Importantly, both PME-1 and HDAC4 associated with human glioma progression, supporting clinical relevance of the identified mechanism. Synthetic lethality induced by both PME-1 and HDAC4 inhibition was dependent on the coexpression of proapoptotic protein BAD. Thus, PME-1-mediated PP2A inhibition is a novel mechanistic explanation for multikinase inhibitor resistance in glioma cells. Clinically, these results may inform patient stratification strategies for future clinical trials with selected kinase inhibitors in glioblastoma multiforme. Cancer Res; 76(23); 7001-11. ©2016 AACR.

  17. A Non-ATP Competitive Inhibitor of BCR-ABL for the Therapy of Imatinib-Resistant Cmls

    DTIC Science & Technology

    2008-05-01

    Network. Further studies are needed to determine the actual cause of Network destruction. STAT3 inhibitor Ursolic acid 16 reduced STAT3 and HSP90...STAT3 were decreased in a dose-dependent manner by Ursolic acid . The disappearance of Bcr-Abl and Jak2 argues that the Network was disrupted as a... Ursolic acid also induces extensive apoptosis induction, as we showed that it induces more than 90% of the Bcr-Abl cells to undergo late state

  18. A computational model of binding thermodynamics: the design of cyclin-dependent kinase 2 inhibitors.

    PubMed

    Sims, Peter A; Wong, Chung F; McCammon, J Andrew

    2003-07-17

    The cyclin-dependent protein kinases are important targets in drug discovery because of their role in cell cycle regulation. In this computational study, we have applied a continuum solvent model to study the interactions between cyclin-dependent kinase 2 (CDK2) and analogues of the clinically tested anticancer agent flavopiridol. The continuum solvent model uses Coulomb's law to account for direct electrostatic interactions, solves the Poisson equation to obtain the electrostatic contributions to solvation energy, and calculates scaled solvent-accessible surface area to account for hydrophobic interactions. The computed free energy of binding gauges the strength of protein-ligand interactions. Our model was first validated through a study on the binding of a number of flavopiridol derivatives to CDK2, and its ability to identify potent inhibitors was observed. The model was then used to aid in the design of novel CDK2 inhibitors with the aid of a computational sensitivity analysis. Some of these hypothetical structures could be significantly more potent than the lead compound flavopiridol. We applied two approaches to gain insights into designing selective inhibitors. One relied on the comparative analysis of the binding pocket for several hundred protein kinases to identify the parts of a lead compound whose modifications might lead to selective compounds. The other was based on building and using homology models for energy calculations. The homology models appear to be able to classify ligand potency into groups but cannot yet give reliable quantitative results.

  19. Evaluation of a tyrosine kinase peptide microarray for tyrosine kinase inhibitor therapy selection in cancer

    PubMed Central

    Labots, Mariette; Gotink, Kristy J; Dekker, Henk; Azijli, Kaamar; van der Mijn, Johannes C; Huijts, Charlotte M; Piersma, Sander R; Jiménez, Connie R; Verheul, Henk M W

    2016-01-01

    Personalized cancer medicine aims to accurately predict the response of individual patients to targeted therapies, including tyrosine kinase inhibitors (TKIs). Clinical implementation of this concept requires a robust selection tool. Here, using both cancer cell lines and tumor tissue from patients, we evaluated a high-throughput tyrosine kinase peptide substrate array to determine its readiness as a selection tool for TKI therapy. We found linearly increasing phosphorylation signal intensities of peptides representing kinase activity along the kinetic curve of the assay with 7.5–10 μg of lysate protein and up to 400 μM adenosine triphosphate (ATP). Basal kinase activity profiles were reproducible with intra- and inter-experiment coefficients of variation of <15% and <20%, respectively. Evaluation of 14 tumor cell lines and tissues showed similar consistently high phosphorylated peptides in their basal profiles. Incubation of four patient-derived tumor lysates with the TKIs dasatinib, sunitinib, sorafenib and erlotinib primarily caused inhibition of substrates that were highly phosphorylated in the basal profile analyses. Using recombinant Src and Axl kinase, relative substrate specificity was demonstrated for a subset of peptides, as their phosphorylation was reverted by co-incubation with a specific inhibitor. In conclusion, we demonstrated robust technical specifications of this high-throughput tyrosine kinase peptide microarray. These features required as little as 5–7 μg of protein per sample, facilitating clinical implementation as a TKI selection tool. However, currently available peptide substrates can benefit from an enhancement of the differential potential for complex samples such as tumor lysates. We propose that mass spectrometry-based phosphoproteomics may provide such an enhancement by identifying more discriminative peptides. PMID:27980342

  20. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors.

    PubMed

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

    2016-04-29

    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.

  1. Assessment of tumor response to tyrosine kinase inhibitors

    PubMed Central

    Lowery, Amanda; Han, Zhaozhong

    2015-01-01

    This review briefly summarizes recent developments in the use of non-invasive imaging to assess tumor response to TKI therapy. Receptor tyrosine kinases play important roles in cancer development. A new class of drugs, tyrosine kinase inhibitors (TKI) can induce rapid and dramatic tumor suppression when administered to carefully selected patient groups. Identifying these patients with responding tumors prior to or shortly after the initiation of therapy remains challenging. The gold standard of response assessment has been by invasive biopsies used in biological and biochemical procedures. Advances in non-invasive imaging at the anatomical, functional and molecular level have enabled the early detection of tumor response; sometimes within days of beginning treatment. The growing area of molecular imaging has spurred the discovery of novel targeting peptides to bind TKI responding tumors. The emergence of targeted, quick responding imaging probes advances the field of cancer management towards the goal of personalized medicine. PMID:21622159

  2. Reduction of Blood Amyloid-β Oligomers in Alzheimer's Disease Transgenic Mice by c-Abl Kinase Inhibition.

    PubMed

    Estrada, Lisbell D; Chamorro, David; Yañez, María José; Gonzalez, Marcelo; Leal, Nancy; von Bernhardi, Rommy; Dulcey, Andrés E; Marugan, Juan; Ferrer, Marc; Soto, Claudio; Zanlungo, Silvana; Inestrosa, Nibaldo C; Alvarez, Alejandra R

    2016-10-04

    One of the pathological hallmarks of Alzheimer's disease (AD) is the presence of amyloid plaques, which are deposits of misfolded and aggregated amyloid-beta peptide (Aβ). The role of the c-Abl tyrosine kinase in Aβ-mediated neurodegeneration has been previously reported. Here, we investigated the therapeutic potential of inhibiting c-Abl using imatinib. We developed a novel method, based on a technique used to detect prions (PMCA), to measure minute amounts of misfolded-Aβ in the blood of AD transgenic mice. We found that imatinib reduces Aβ-oligomers in plasma, which correlates with a reduction of AD brain features such as plaques and oligomers accumulation, neuroinflammation, and cognitive deficits. Cells exposed to imatinib and c-Abl KO mice display decreased levels of β-CTF fragments, suggesting that an altered processing of the amyloid-beta protein precursor is the most probable mechanism behind imatinib effects. Our findings support the role of c-Abl in Aβ accumulation and AD, and propose AD-PMCA as a new tool to evaluate AD progression and screening for drug candidates.

  3. Action of the Src family kinase inhibitor, dasatinib (BMS-354825), on human prostate cancer cells.

    PubMed

    Nam, Sangkil; Kim, Donghwa; Cheng, Jin Q; Zhang, Shumin; Lee, Ji-Hyun; Buettner, Ralf; Mirosevich, Janni; Lee, Francis Y; Jove, Richard

    2005-10-15

    Src family kinases (SFK) are currently being investigated as targets for treatment strategies in various cancers. The novel SFK/Abl inhibitor, dasatinib (BMS-354825), is a promising therapeutic agent with oral bioavailability. Dasatinib has been shown to inhibit growth of Bcr-Abl-dependent chronic myeloid leukemia xenografts in nude mice. Dasatinib also has been shown to have activity against cultured human prostate and breast cancer cells. However, the molecular mechanism by which dasatinib acts on epithelial tumor cells remains unknown. In this study, we show that dasatinib blocks the kinase activities of the SFKs, Lyn, and Src, in human prostate cancer cells at low nanomolar concentrations. Moreover, focal adhesion kinase and Crk-associated substrate (p130(CAS)) signaling downstream of SFKs are also inhibited at similar concentrations of dasatinib. Consistent with inhibition of these signaling pathways, dasatinib suppresses cell adhesion, migration, and invasion of prostate cancer cells at low nanomolar concentrations. Therefore, dasatinib has potential as a therapeutic agent for metastatic prostate cancers harboring activated SFK and focal adhesion kinase signaling.

  4. Targeting abnormal DNA double strand break repair in tyrosine kinase inhibitor-resistant chronic myeloid leukemias

    PubMed Central

    Tobin, Lisa A.; Robert, Carine; Rapoport, Aaron P.; Gojo, Ivana; Baer, Maria R.; Tomkinson, Alan E.; Rassool, Feyruz V.

    2013-01-01

    Resistance to imatinib (IM) and other BCR-ABL1 tyrosine kinase inhibitors (TKI)s is an increasing problem in leukemias caused by expression of BCR-ABL1. Since chronic myeloid leukemia (CML) cell lines expressing BCR-ABL1 utilize an alternative non-homologous end-joining pathway (ALT NHEJ) to repair DNA double strand breaks (DSB)s, we asked whether this repair pathway is a novel therapeutic target in TKI-resistant disease. Notably, the steady state levels of two ALT NHEJ proteins, poly-(ADP-ribose) polymerase 1 (PARP1) and DNA ligase IIIα were increased in the BCR-ABL1-positive CML cell line K562 and, to a greater extent, in its imatinib resistant (IMR) derivative. Incubation of these cell lines with a combination of DNA ligase and PARP inhibitors inhibited ALT NHEJ and selectively decreased survival with the effect being greater in the IMR derivative. Similar results were obtained with TKI-resistant derivatives of two hematopoietic cell lines that had been engineered to stably express BCR-ABL1. Together our results show that the sensitivity of cell lines expressing BCR-ABL1 to the combination of DNA ligase and PARP inhibitors correlates with the steady state levels of PARP1 and DNA ligase IIIα, and ALT NHEJ activity. Importantly, analysis of clinical samples from CML patients confirmed that the expression levels of PARP1 and DNA ligase IIIα correlated with sensitivity to the DNA repair inhibitor combination. Thus, the expression levels of PARP1 and DNA ligase IIIα serve as biomarkers to identify a subgroup of CML patients who may be candidates for therapies that target the ALT NHEJ pathway when treatment with TKIs has failed. PMID:22641215

  5. Crystal structure of the FLT3 kinase domain bound to the inhibitor quizartinib (AC220)

    SciTech Connect

    Zorn, Julie A.; Wang, Qi; Fujimura, Eric; Barros, Tiago; Kuriyan, John; Boggon, Titus J.

    2015-04-02

    More than 30% of acute myeloid leukemia (AML) patients possess activating mutations in the receptor tyrosine kinase FMS-like tyrosine kinase 3 or FLT3. A small-molecule inhibitor of FLT3 (known as quizartinib or AC220) that is currently in clinical trials appears promising for the treatment of AML. Here, we report the co-crystal structure of the kinase domain of FLT3 in complex with quizartinib. FLT3 with quizartinib bound adopts an “Abl-like” inactive conformation with the activation loop stabilized in the “DFG-out” orientation and folded back onto the kinase domain. This conformation is similar to that observed for the uncomplexed intracellular domain of FLT3 as well as for related receptor tyrosine kinases, except for a localized induced fit in the activation loop. The co-crystal structure reveals the interactions between quizartinib and the active site of FLT3 that are key for achieving its high potency against both wild-type FLT3 as well as a FLT3 variant observed in many AML patients. This co-complex further provides a structural rationale for quizartinib-resistance mutations.

  6. Crystal structure of the FLT3 kinase domain bound to the inhibitor quizartinib (AC220)

    DOE PAGES

    Zorn, Julie A.; Wang, Qi; Fujimura, Eric; ...

    2015-04-02

    More than 30% of acute myeloid leukemia (AML) patients possess activating mutations in the receptor tyrosine kinase FMS-like tyrosine kinase 3 or FLT3. A small-molecule inhibitor of FLT3 (known as quizartinib or AC220) that is currently in clinical trials appears promising for the treatment of AML. Here, we report the co-crystal structure of the kinase domain of FLT3 in complex with quizartinib. FLT3 with quizartinib bound adopts an “Abl-like” inactive conformation with the activation loop stabilized in the “DFG-out” orientation and folded back onto the kinase domain. This conformation is similar to that observed for the uncomplexed intracellular domain ofmore » FLT3 as well as for related receptor tyrosine kinases, except for a localized induced fit in the activation loop. The co-crystal structure reveals the interactions between quizartinib and the active site of FLT3 that are key for achieving its high potency against both wild-type FLT3 as well as a FLT3 variant observed in many AML patients. This co-complex further provides a structural rationale for quizartinib-resistance mutations.« less

  7. Compound Selectivity and Target Residence Time of Kinase Inhibitors Studied with Surface Plasmon Resonance.

    PubMed

    Willemsen-Seegers, Nicole; Uitdehaag, Joost C M; Prinsen, Martine B W; de Vetter, Judith R F; de Man, Jos; Sawa, Masaaki; Kawase, Yusuke; Buijsman, Rogier C; Zaman, Guido J R

    2017-02-17

    Target residence time (τ) has been suggested to be a better predictor of the biological activity of kinase inhibitors than inhibitory potency (IC50) in enzyme assays. Surface plasmon resonance binding assays for 46 human protein and lipid kinases were developed. The association and dissociation constants of 80 kinase inhibitor interactions were determined. τ and equilibrium affinity constants (KD) were calculated to determine kinetic selectivity. Comparison of τ and KD or IC50 values revealed a strikingly different view on the selectivity of several kinase inhibitors, including the multi-kinase inhibitor ponatinib, which was tested on 10 different kinases. In addition, known pan-Aurora inhibitors resided much longer on Aurora B than on Aurora A, despite having comparable affinity for Aurora A and B. Furthermore, the γ/δ-selective PI3K inhibitor duvelisib and the δ-selective drug idelalisib had similar 20-fold selectivity for δ- over γ-isoform but duvelisib resided much longer on both targets.

  8. Cyclin Dependent Kinase 9 Inhibitors for Cancer Therapy.

    PubMed

    Sonawane, Yogesh A; Taylor, Margaret A; Napoleon, John Victor; Rana, Sandeep; Contreras, Jacob I; Natarajan, Amarnath

    2016-10-13

    Cyclin dependent kinase (CDK) inhibitors have been the topic of intense research for nearly 2 decades due to their widely varied and critical functions within the cell. Recently CDK9 has emerged as a druggable target for the development of cancer therapeutics. CDK9 plays a crucial role in transcription regulation; specifically, CDK9 mediated transcriptional regulation of short-lived antiapoptotic proteins is critical for the survival of transformed cells. Focused chemical libraries based on a plethora of scaffolds have resulted in mixed success with regard to the development of selective CDK9 inhibitors. Here we review the regulation of CDK9, its cellular functions, and common core structures used to target CDK9, along with their selectivity profile and efficacy in vitro and in vivo.

  9. Tyrosine Kinase Inhibitors Regulate OPG through Inhibition of PDGFRβ

    PubMed Central

    Tay, Mei Lin; Lin, Jian-Ming; Bava, Usha; Callon, Karen; Cornish, Jillian; Naot, Dorit; Grey, Andrew

    2016-01-01

    Nilotinib and imatinib are tyrosine kinase inhibitors (TKIs) used in the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). In vitro, imatinib and nilotinib inhibit osteoclastogenesis, and in patients they reduce levels of bone resorption. One of the mechanisms that might underlie these effects is an increase in the production of osteoprotegerin (OPG). In the current work we report that platelet-derived growth factor receptor beta (PDGFRβ) signaling regulates OPG production in vitro. In addition, we have shown that TKIs have effects on RANKL signaling through inhibition of the PDGFRβ and other target receptors. These findings have implications for our understanding of the mechanisms by which TKIs affect osteoclastogenesis, and the role of PDGFRβ signaling in regulating osteoclastogenesis. Further studies are indicated to confirm the clinical effects of PDGFRβ-inhibitors and to elaborate the intracellular pathways that underpin these effects. PMID:27737004

  10. Design, synthesis and structure-activity relationships of novel biarylamine-based Met kinase inhibitors

    SciTech Connect

    Williams, David K; Chen, Xiao-Tao; Tarby, Christine; Kaltenbach, Robert; Cai, Zhen-Wei; Tokarski, John S; An, Yongmi; Sack, John S; Wautlet, Barri; Gullo-Brown, Johnni; Henley, Benjamin J; Jeyaseelan, Robert; Kellar, Kristen; Manne, Veeraswamy; Trainor, George L; Lombardo, Louis J; Fargnoli, Joseph; Borzilleri, Robert M

    2010-09-03

    Biarylamine-based inhibitors of Met kinase have been identified. Lead compounds demonstrate nanomolar potency in Met kinase biochemical assays and significant activity in the Met-driven GTL-16 human gastric carcinoma cell line. X-ray crystallography revealed that these compounds adopt a bioactive conformation, in the kinase domain, consistent with that previously seen with 2-pyridone-based Met kinase inhibitors. Compound 9b demonstrated potent in vivo antitumor activity in the GTL-16 human tumor xenograft model.

  11. Emerging Drug Profile: Cyclin-Dependent Kinase Inhibitors

    PubMed Central

    Blachly, James S.; Byrd, John C.

    2013-01-01

    As the rational application of targeted therapies in cancer supplants traditional cytotoxic chemotherapy, there is an ever-greater need for a thorough understanding of the complex machinery of the cell and an application of this knowledge to the development of novel therapeutics and combinations of agents. Here, we review the current state of knowledge of the class of targeted agents known as cyclin-dependent kinase (CDK) inhibitors, with a focus on chronic lymphocytic leukemia (CLL). Flavopiridol (alvocidib) is the best studied of the CDK inhibitors, producing a dramatic cytotoxic effect in vitro and in vivo, with the principal limiting factor of acute tumor lysis. Unfortunately, flavopiridol has a narrow therapeutic window and is relatively non-selective with several off-target (i.e. non-CDK) effects, which prompted development of the second-generation CDK inhibitor dinaciclib. Dinaciclib appears to be both more potent and selective than flavopiridol, with at least an order of magnitude greater therapeutic index, and is currently in phase III clinical trials. In additional to flavopiridol and dinaciclib, we also review the current state of other members of this class, and provide commentary as to the future direction of combination therapy including CDK inhibitors. PMID:23488658

  12. Development of Selective Covalent Janus Kinase 3 Inhibitors.

    PubMed

    Tan, Li; Akahane, Koshi; McNally, Randall; Reyskens, Kathleen M S E; Ficarro, Scott B; Liu, Suhu; Herter-Sprie, Grit S; Koyama, Shohei; Pattison, Michael J; Labella, Katherine; Johannessen, Liv; Akbay, Esra A; Wong, Kwok-Kin; Frank, David A; Marto, Jarrod A; Look, Thomas A; Arthur, J Simon C; Eck, Michael J; Gray, Nathanael S

    2015-08-27

    The Janus kinases (JAKs) and their downstream effectors, signal transducer and activator of transcription proteins (STATs), form a critical immune cell signaling circuit, which is of fundamental importance in innate immunity, inflammation, and hematopoiesis, and dysregulation is frequently observed in immune disease and cancer. The high degree of structural conservation of the JAK ATP binding pockets has posed a considerable challenge to medicinal chemists seeking to develop highly selective inhibitors as pharmacological probes and as clinical drugs. Here we report the discovery and optimization of 2,4-substituted pyrimidines as covalent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Investigation of structure-activity relationship (SAR) utilizing biochemical and transformed Ba/F3 cellular assays resulted in identification of potent and selective inhibitors such as compounds 9 and 45. A 2.9 Å cocrystal structure of JAK3 in complex with 9 confirms the covalent interaction. Compound 9 exhibited decent pharmacokinetic properties and is suitable for use in vivo. These inhibitors provide a set of useful tools to pharmacologically interrogate JAK3-dependent biology.

  13. Role of tyrosine-kinase inhibitors in myeloproliferative neoplasms: comparative lessons learned

    PubMed Central

    Pinilla-Ibarz, Javier; Sweet, Kendra L; Corrales-Yepez, Gabriela M; Komrokji, Rami S

    2016-01-01

    An important pathogenetic distinction in the classification of myeloproliferative neoplasms (MPNs) is the presence or absence of the BCR–ABL fusion gene, which encodes a unique oncogenic tyrosine kinase. The BCR–ABL fusion, caused by the formation of the Philadelphia chromosome (Ph) through translocation, constitutes the disease-initiating event in chronic myeloid leukemia. The development of successive BCR–ABL-targeted tyrosine-kinase inhibitors has led to greatly improved outcomes in patients with chronic myeloid leukemia, including high rates of complete hematologic, cytogenetic, and molecular responses. Such levels of treatment success have long been elusive for patients with Ph-negative MPNs, because of the difficulties in identifying specific driver proteins suitable as drug targets. However, in recent years an improved understanding of the complex pathobiology of classic Ph-negative MPNs, characterized by variable, overlapping multimutation profiles, has prompted the development of better and more broadly targeted (to pathway rather than protein) treatment options, particularly JAK inhibitors. In classic Ph-negative MPNs, overactivation of JAK-dependent signaling pathways is a central pathogenic mechanism, and mutually exclusive mutations in JAK2, MPL, and CALR linked to aberrant JAK activation are now recognized as key drivers of disease progression in myelofibrosis (MF). In clinical trials, the JAK1/JAK2 inhibitor ruxolitinib – the first therapy approved for MF worldwide – improved disease-related splenomegaly and symptoms independent of JAK2V617F mutational status, and prolonged survival compared with placebo or standard therapy in patients with advanced MF. In separate trials, ruxolitinib also provided comprehensive hematologic control in patients with another Ph-negative MPN – polycythemia vera. However, complete cytogenetic or molecular responses with JAK inhibitors alone are normally not observed, underscoring the need for novel

  14. Development of covalent inhibitors that can overcome resistance to first-generation FGFR kinase inhibitors.

    PubMed

    Tan, Li; Wang, Jun; Tanizaki, Junko; Huang, Zhifeng; Aref, Amir R; Rusan, Maria; Zhu, Su-Jie; Zhang, Yiyun; Ercan, Dalia; Liao, Rachel G; Capelletti, Marzia; Zhou, Wenjun; Hur, Wooyoung; Kim, NamDoo; Sim, Taebo; Gaudet, Suzanne; Barbie, David A; Yeh, Jing-Ruey Joanna; Yun, Cai-Hong; Hammerman, Peter S; Mohammadi, Moosa; Jänne, Pasi A; Gray, Nathanael S

    2014-11-11

    The human FGF receptors (FGFRs) play critical roles in various human cancers, and several FGFR inhibitors are currently under clinical investigation. Resistance usually results from selection for mutant kinases that are impervious to the action of the drug or from up-regulation of compensatory signaling pathways. Preclinical studies have demonstrated that resistance to FGFR inhibitors can be acquired through mutations in the FGFR gatekeeper residue, as clinically observed for FGFR4 in embryonal rhabdomyosarcoma and neuroendocrine breast carcinomas. Here we report on the use of a structure-based drug design to develop two selective, next-generation covalent FGFR inhibitors, the FGFR irreversible inhibitors 2 (FIIN-2) and 3 (FIIN-3). To our knowledge, FIIN-2 and FIIN-3 are the first inhibitors that can potently inhibit the proliferation of cells dependent upon the gatekeeper mutants of FGFR1 or FGFR2, which confer resistance to first-generation clinical FGFR inhibitors such as NVP-BGJ398 and AZD4547. Because of the conformational flexibility of the reactive acrylamide substituent, FIIN-3 has the unprecedented ability to inhibit both the EGF receptor (EGFR) and FGFR covalently by targeting two distinct cysteine residues. We report the cocrystal structure of FGFR4 with FIIN-2, which unexpectedly exhibits a "DFG-out" covalent binding mode. The structural basis for dual FGFR and EGFR targeting by FIIN3 also is illustrated by crystal structures of FIIN-3 bound with FGFR4 V550L and EGFR L858R. These results have important implications for the design of covalent FGFR inhibitors that can overcome clinical resistance and provide the first example, to our knowledge, of a kinase inhibitor that covalently targets cysteines located in different positions within the ATP-binding pocket.

  15. Development of covalent inhibitors that can overcome resistance to first-generation FGFR kinase inhibitors

    PubMed Central

    Tan, Li; Wang, Jun; Tanizaki, Junko; Huang, Zhifeng; Aref, Amir R.; Rusan, Maria; Zhu, Su-Jie; Zhang, Yiyun; Ercan, Dalia; Liao, Rachel G.; Capelletti, Marzia; Zhou, Wenjun; Hur, Wooyoung; Kim, NamDoo; Sim, Taebo; Gaudet, Suzanne; Barbie, David A.; Yeh, Jing-Ruey Joanna; Yun, Cai-Hong; Hammerman, Peter S.; Mohammadi, Moosa; Jänne, Pasi A.; Gray, Nathanael S.

    2014-01-01

    The human FGF receptors (FGFRs) play critical roles in various human cancers, and several FGFR inhibitors are currently under clinical investigation. Resistance usually results from selection for mutant kinases that are impervious to the action of the drug or from up-regulation of compensatory signaling pathways. Preclinical studies have demonstrated that resistance to FGFR inhibitors can be acquired through mutations in the FGFR gatekeeper residue, as clinically observed for FGFR4 in embryonal rhabdomyosarcoma and neuroendocrine breast carcinomas. Here we report on the use of a structure-based drug design to develop two selective, next-generation covalent FGFR inhibitors, the FGFR irreversible inhibitors 2 (FIIN-2) and 3 (FIIN-3). To our knowledge, FIIN-2 and FIIN-3 are the first inhibitors that can potently inhibit the proliferation of cells dependent upon the gatekeeper mutants of FGFR1 or FGFR2, which confer resistance to first-generation clinical FGFR inhibitors such as NVP-BGJ398 and AZD4547. Because of the conformational flexibility of the reactive acrylamide substituent, FIIN-3 has the unprecedented ability to inhibit both the EGF receptor (EGFR) and FGFR covalently by targeting two distinct cysteine residues. We report the cocrystal structure of FGFR4 with FIIN-2, which unexpectedly exhibits a “DFG-out” covalent binding mode. The structural basis for dual FGFR and EGFR targeting by FIIN3 also is illustrated by crystal structures of FIIN-3 bound with FGFR4 V550L and EGFR L858R. These results have important implications for the design of covalent FGFR inhibitors that can overcome clinical resistance and provide the first example, to our knowledge, of a kinase inhibitor that covalently targets cysteines located in different positions within the ATP-binding pocket. PMID:25349422

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

    SciTech Connect

    Jin, Hyeon-Ok; Hong, Sung-Eun; Kim, Chang Soon; Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora; Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun; Park, In-Chul; Lee, Jin Kyung

    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.

  17. Crystal structure of inhibitor of ;#954;B kinase [beta

    SciTech Connect

    Xu, Guozhou; Lo, Yu-Chih; Li, Qiubai; Napolitano, Gennaro; Wu, Xuefeng; Jiang, Xuliang; Dreano, Michel; Karin, Michael; Wu, Hao

    2011-07-26

    Inhibitor of {kappa}B (I{kappa}B) kinase (IKK) phosphorylates I{kappa}B proteins, leading to their degradation and the liberation of nuclear factor {kappa}B for gene transcription. Here we report the crystal structure of IKK{beta} in complex with an inhibitor, at a resolution of 3.6 {angstrom}. The structure reveals a trimodular architecture comprising the kinase domain, a ubiquitin-like domain (ULD) and an elongated, {alpha}-helical scaffold/dimerization domain (SDD). Unexpectedly, the predicted leucine zipper and helix-loop-helix motifs do not form these structures but are part of the SDD. The ULD and SDD mediate a critical interaction with I{kappa}B{alpha} that restricts substrate specificity, and the ULD is also required for catalytic activity. The SDD mediates IKK{beta} dimerization, but dimerization per se is not important for maintaining IKK{beta} activity and instead is required for IKK{beta} activation. Other IKK family members, IKK{alpha}, TBK1 and IKK-i, may have a similar trimodular architecture and function.

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

    PubMed

    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).

  19. Kinase inhibitors as potential agents in the treatment of multiple myeloma

    PubMed Central

    Abramson, Hanley N.

    2016-01-01

    Recent years have witnessed a dramatic increase in the number of therapeutic options available for the treatment of multiple myeloma (MM) - from immunomodulating agents to proteasome inhibitors to histone deacetylase (HDAC) inhibitors and, most recently, monoclonal antibodies. Used in conjunction with autologous hematopoietic stem cell transplantation, these modalities have nearly doubled the disease's five-year survival rate over the last three decades to about 50%. In spite of these advances, MM still is considered incurable as resistance and relapse are common. While small molecule protein kinase inhibitors have made inroads in the therapy of a number of cancers, to date their application to MM has been less than successful. Focusing on MM, this review examines the roles played by a number of kinases in driving the malignant state and the rationale for target development in the design of a number of kinase inhibitors that have demonstrated anti-myeloma activity in both in vitro and in vivo xenograph models, as well as those that have entered clinical trials. Among the targets and their inhibitors examined are receptor and non-receptor tyrosine kinases, cell cycle control kinases, the PI3K/AKT/mTOR pathway kinases, protein kinase C, mitogen-activated protein kinase, glycogen synthase kinase, casein kinase, integrin-linked kinase, sphingosine kinase, and kinases involved in the unfolded protein response. PMID:27655636

  20. Novel bone-targeted Src tyrosine kinase inhibitor drug discovery.

    PubMed

    Shakespeare, William C; Metcalf, Chester A; Wang, Yihan; Sundaramoorthi, Raji; Keenan, Terence; Weigele, Manfred; Bohacek, Regine S; Dalgarno, David C; Sawyer, Tomi K

    2003-09-01

    Bone-targeted Src tyrosine kinase (STK) inhibitors have recently been developed for the treatment of osteoporosis and cancer-related bone diseases. The concept of bone targeting derives from bisphosphonates, and from the evolution of such molecules in terms of therapeutic efficacy for the treatment of bone disorders. Interestingly, some of the earliest bisphosphonates were recognized for their ability to inhibit calcium carbonate precipitation (scaling) by virtue of their affinity to chelate calcium. This chelating property was subsequently exploited in the development of bisphosphonate analogs as inhibitors of the bone-resorbing cells known as osteoclasts, giving rise to breakthrough medicines, such as Fosamax (for the treatment of osteoporosis) and Zometa (for the treatment of osteoporosis and bone metastases). Relative to these milestone achievements, there is a tremendous opportunity to explore beyond the limited chemical space (functional group diversity) of such bisphosphonates to design novel bone-targeting moieties, which may be used to develop other classes of promising small-molecule drugs affecting different biological pathways. Here, we review studies focused on bone-targeted inhibitors of STK, a key enzyme in osteoclast-dependent bone resorption. Two strategies are described relative to bone-targeted STK inhibitor drug discovery: (i) the development of novel Src homology (SH)-2 inhibitors incorporating non-hydrolyzable phosphotyrosine mimics and exhibiting molecular recognition and bone-targeting properties, leading to the in vivo-effective lead compound AP-22408; and (ii) the development of novel ATP-based Src kinase inhibitors incorporating bone-targeting moieties, leading to the in vivo-effective lead compound AP-23236. In summary, AP-22408 and AP-23236, which differ mechanistically by virtue of blocking Src-dependent non-catalytic or catalytic activities in osteoclasts, exemplify ARIAD Pharmaceuticals' structure-based design of novel bone

  1. Leads for antitubercular compounds from kinase inhibitor library screens.

    PubMed

    Magnet, Sophie; Hartkoorn, Ruben C; Székely, Rita; Pató, János; Triccas, James A; Schneider, Patricia; Szántai-Kis, Csaba; Orfi, László; Chambon, Marc; Banfi, Damiano; Bueno, Manuel; Turcatti, Gerardo; Kéri, György; Cole, Stewart T

    2010-11-01

    Discovering new drugs to treat tuberculosis more efficiently and to overcome multidrug resistance is a world health priority. To find antimycobacterial scaffolds, we screened a kinase inhibitor library of more than 12,000 compounds using an integrated strategy involving whole cell-based assays with Corynebacterium glutamicum and Mycobacterium tuberculosis, and a target-based assay with the protein kinase PknA. Seventeen "hits" came from the whole cell-based screening approach, from which three displayed minimal inhibitory concentrations (MIC) against M. tuberculosis below 10μM and were non-mutagenic and non-cytotoxic. Two of these hits were specific for M. tuberculosis versus C. glutamicum and none of them was found to inhibit the essential serine/threonine protein kinases, PknA and PknB present in both bacteria. One of the most active hits, VI-18469, had a benzoquinoxaline pharmacophore while another, VI-9376, is structurally related to a new class of antimycobacterial agents, the benzothiazinones (BTZ). Like the BTZ, VI-9376 was shown to act on the essential enzyme decaprenylphosphoryl-β-D-ribose 2'-epimerase, DprE1, required for arabinan synthesis.

  2. Identification of Novel Small Molecule Inhibitors of Oncogenic RET Kinase.

    PubMed

    Moccia, Marialuisa; Liu, Qingsong; Guida, Teresa; Federico, Giorgia; Brescia, Annalisa; Zhao, Zheng; Choi, Hwan Geun; Deng, Xianming; Tan, Li; Wang, Jinhua; Billaud, Marc; Gray, Nathanael S; Carlomagno, Francesca; Santoro, Massimo

    2015-01-01

    Oncogenic mutation of the RET receptor tyrosine kinase is observed in several human malignancies. Here, we describe three novel type II RET tyrosine kinase inhibitors (TKI), ALW-II-41-27, XMD15-44 and HG-6-63-01, that inhibit the cellular activity of oncogenic RET mutants at two digit nanomolar concentration. These three compounds shared a 3-trifluoromethyl-4-methylpiperazinephenyl pharmacophore that stabilizes the 'DFG-out' inactive conformation of RET activation loop. They blocked RET-mediated signaling and proliferation with an IC50 in the nM range in fibroblasts transformed by the RET/C634R and RET/M918T oncogenes. They also inhibited autophosphorylation of several additional oncogenic RET-derived point mutants and chimeric oncogenes. At a concentration of 10 nM, ALW-II-41-27, XMD15-44 and HG-6-63-01 inhibited RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles; they also inhibited proliferation of cancer, but not non-tumoral Nthy-ori-3-1, thyroid cells, with an IC50 in the nM range. The three compounds were capable of inhibiting the 'gatekeeper' V804M mutant which confers substantial resistance to established RET inhibitors. In conclusion, we have identified a type II TKI scaffold, shared by ALW-II-41-27, XMD15-44 and HG-6-63-01, that may be used as novel lead for the development of novel agents for the treatment of cancers harboring oncogenic activation of RET.

  3. Identification of Novel Small Molecule Inhibitors of Oncogenic RET Kinase

    PubMed Central

    Moccia, Marialuisa; Liu, Qingsong; Guida, Teresa; Federico, Giorgia; Brescia, Annalisa; Zhao, Zheng; Choi, Hwan Geun; Deng, Xianming; Tan, Li; Wang, Jinhua; Billaud, Marc; Gray, Nathanael S.

    2015-01-01

    Oncogenic mutation of the RET receptor tyrosine kinase is observed in several human malignancies. Here, we describe three novel type II RET tyrosine kinase inhibitors (TKI), ALW-II-41-27, XMD15-44 and HG-6-63-01, that inhibit the cellular activity of oncogenic RET mutants at two digit nanomolar concentration. These three compounds shared a 3-trifluoromethyl-4-methylpiperazinephenyl pharmacophore that stabilizes the ‘DFG-out’ inactive conformation of RET activation loop. They blocked RET-mediated signaling and proliferation with an IC50 in the nM range in fibroblasts transformed by the RET/C634R and RET/M918T oncogenes. They also inhibited autophosphorylation of several additional oncogenic RET-derived point mutants and chimeric oncogenes. At a concentration of 10 nM, ALW-II-41-27, XMD15-44 and HG-6-63-01 inhibited RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles; they also inhibited proliferation of cancer, but not non-tumoral Nthy-ori-3-1, thyroid cells, with an IC50 in the nM range. The three compounds were capable of inhibiting the ‘gatekeeper’ V804M mutant which confers substantial resistance to established RET inhibitors. In conclusion, we have identified a type II TKI scaffold, shared by ALW-II-41-27, XMD15-44 and HG-6-63-01, that may be used as novel lead for the development of novel agents for the treatment of cancers harboring oncogenic activation of RET. PMID:26046350

  4. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton.

    PubMed

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A

    2013-08-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness.

  5. Quick evaluation of kinase inhibitors by surface plasmon resonance using single-site specifically biotinylated kinases.

    PubMed

    Kitagawa, Daisuke; Gouda, Masaki; Kirii, Yasuyuki

    2014-03-01

    In evaluating kinase inhibitors, kinetic parameters such as association/dissociation rate constants are valuable information, as are equilibrium parameters KD and IC50 values. Surface plasmon resonance (SPR) is a powerful technique to investigate these parameters. However, results are often complicated because of impaired conformations by inappropriate conditions required for protein immobilization and/or heterogeneity of the orientation of immobilization. In addition, conventional SPR experiments are generally time-consuming. Here we introduce the use of single-site specifically biotinylated kinases combined with a multichannel SPR device to improve such problems. Kinetic parameters of four compounds-staurosporine, dasatinib, sunitinib, and lapatinib-against six kinases were determined by the ProteOn XPR36 system. The very slow off-rate of lapatinib from the epidermal growth factor receptor and dasatinib from Bruton's tyrosine kinase and colony stimulating factor 1 receptor (CSF1R) were confirmed. Furthermore, IC50 values were determined by an activity-based assay. Evaluating both physicochemical and biochemical properties would help to understand the detailed character of the compound.

  6. Dysregulation of catalase activity in newborn myocytes during hypoxia is mediated by c-Abl tyrosine kinase.

    PubMed

    Cabigas, E Bernadette; Liu, Jie; Boopathy, Archana V; Che, Pao Lin; Crawford, Brian H; Baroi, Gitangali; Bhutani, Srishti; Shen, Ming; Wagner, Mary B; Davis, Michael E

    2015-01-01

    In the adult heart, catalase (CAT) activity increases appropriately with increasing levels of hydrogen peroxide, conferring cardioprotection. This mechanism is absent in the newborn for unknown reasons. In the present study, we examined how the posttranslational modification of CAT contributes to its activation during hypoxia/ischemia and the role of c-Abl tyrosine kinase in this process. Hypoxia studies were carried out using primary cardiomyocytes from adult (>8 weeks) and newborn rats. Following hypoxia, the ratio of phosphorylated to total CAT and c-Abl in isolated newborn rat myocytes did not increase and were significantly lower (1.3- and 4.2-fold, respectively; P < .05) than their adult counterparts. Similarly, there was a significant association (P < .0005) between c-Abl and CAT in adult cells following hypoxia (30.9 ± 8.2 to 70.7 ± 13.1 au) that was absent in newborn myocytes. Although ubiquitination of CAT was higher in newborns compared to adults following hypoxia, inhibition of this did not improve CAT activity. When a c-Abl activator (5-(1,3-diaryl-1H-pyrazol-4-yl)hydantoin [DPH], 200 µmol/L) was administered prior to hypoxia, not only CAT activity was significantly increased (P < .05) but also phosphorylation levels were also significantly improved (P < .01) in these newborn myocytes. Additionally, ischemia-reperfusion (IR) studies were performed using newborn (4-5 days) rabbit hearts perfused in a Langendorff method. The DPH given as an intracardiac injection into the right ventricle of newborn rabbit resulted in a significant improvement (P < .002) in the recovery of developed pressure after IR, a key indicator of cardiac function (from 74.6% ± 6.6% to 118.7% ± 10.9%). In addition, CAT activity was increased 3.92-fold (P < .02) in the same DPH-treated hearts. Addition of DPH to adult rabbits in contrast had no significant effect (from 71.3% ± 10.7% to 59.4% ± 12.1%). Therefore, in the newborn, decreased phosphorylation of CAT by c-Abl

  7. ON012380: A Non-ATP Competitive Inhibitor of BCR-ABL for the Therapy of Imatinib-Resistant CMLs

    DTIC Science & Technology

    2010-05-01

    applications including monosomy 7 MDS, imatinib-resistant CML, and myeloproliferative neoplasms that develop resistance to ATP-competitive agents. Keywords JAK2...and myeloproliferative neoplasms where JAK2 is aberrantly activated. In the past few years, several cases have been reported in which both the BCR...found to be dual inhibitors of BCR-ABL and JAK-2, 8 which makes them ideal agents for the treatment of other myeloproliferative diseases in addition

  8. Identification of “Preferred” Human Kinase Inhibitors for Sleeping Sickness Lead Discovery. Are Some Kinases Better than Others for Inhibitor Repurposing?

    PubMed Central

    2016-01-01

    A kinase-targeting cell-based high-throughput screen (HTS) against Trypanosoma brucei was recently reported, and this screening set included the Published Kinase Inhibitor Set (PKIS). From the PKIS was identified 53 compounds with pEC50 ≥ 6. Utilizing the published data available for the PKIS, a statistical analysis of these active antiparasitic compounds was performed, allowing identification of a set of human kinases having inhibitors that show a high likelihood for blocking T. brucei cellular proliferation in vitro. This observation was confirmed by testing other established inhibitors of these human kinases and by mining past screening campaigns at GlaxoSmithKline. Overall, although the parasite targets of action are not known, inhibitors of this set of human kinases displayed an enhanced hit rate relative to a random kinase-targeting HTS campaign, suggesting that repurposing efforts should focus primarily on inhibitors of these specific human kinases. We therefore term this statistical analysis-driven approach “preferred lead repurposing”. PMID:26998514

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

    PubMed

    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.

  10. The c-Abl inhibitor, nilotinib, protects dopaminergic neurons in a preclinical animal model of Parkinson's disease.

    PubMed

    Karuppagounder, Senthilkumar S; Brahmachari, Saurav; Lee, Yunjong; Dawson, Valina L; Dawson, Ted M; Ko, Han Seok

    2014-05-02

    c-Abl is activated in the brain of Parkinson's disease (PD) patients and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice where it inhibits parkin through tyrosine phosphorylation leading to the accumulation of parkin substrates, and neuronal cell death. In the present study, we evaluated the in vivo efficacy of nilotinib, a brain penetrant c-Abl inhibitor, in the acute MPTP-induced model of PD. Our results show that administration of nilotinib reduces c-Abl activation and the levels of the parkin substrate, PARIS, resulting in prevention of dopamine (DA) neuron loss and behavioral deficits following MPTP intoxication. On the other hand, we observe no reduction in the tyrosine phosphorylation of parkin and the parkin substrate, AIMP2 suggesting that the protective effect of nilotinib may, in part, be parkin-independent or to the pharmacodynamics properties of nilotinib. This study provides a strong rationale for testing other brain permeable c-Abl inhibitors as potential therapeutic agents for the treatment of PD.

  11. The c-Abl inhibitor, Nilotinib, protects dopaminergic neurons in a preclinical animal model of Parkinson's disease

    PubMed Central

    Karuppagounder, Senthilkumar S.; Brahmachari, Saurav; Lee, Yunjong; Dawson, Valina L.; Dawson, Ted M.; Ko, Han Seok

    2014-01-01

    c-Abl is activated in the brain of Parkinson's disease (PD) patients and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice where it inhibits parkin through tyrosine phosphorylation leading to the accumulation of parkin substrates, and neuronal cell death. In the present study, we evaluated the in vivo efficacy of nilotinib, a brain penetrant c-Abl inhibitor, in the acute MPTP-induced model of PD. Our results show that administration of nilotinib reduces c-Abl activation and the levels of the parkin substrate, PARIS, resulting in prevention of dopamine (DA) neuron loss and behavioral deficits following MPTP intoxication. On the other hand, we observe no reduction in the tyrosine phosphorylation of parkin and the parkin substrate, AIMP2 suggesting that the protective effect of nilotinib may, in part, be parkin-independent or to the pharmacodynamics properties of nilotinib. This study provides a strong rationale for testing other brain permeable c-Abl inhibitors as potential therapeutic agents for the treatment of PD. PMID:24786396

  12. Design and Synthesis of Novel Macrocyclic Mer Tyrosine Kinase Inhibitors.

    PubMed

    Wang, Xiaodong; Liu, Jing; Zhang, Weihe; Stashko, Michael A; Nichols, James; Miley, Michael J; Norris-Drouin, Jacqueline; Chen, Zhilong; Machius, Mischa; DeRyckere, Deborah; Wood, Edgar; Graham, Douglas K; Earp, H Shelton; Kireev, Dmitri; Frye, Stephen V

    2016-12-08

    Mer tyrosine kinase (MerTK) is aberrantly elevated in various tumor cells and has a normal anti-inflammatory role in the innate immune system. Inhibition of MerTK may provide dual effects against these MerTK-expressing tumors through reducing cancer cell survival and redirecting the innate immune response. Recently, we have designed novel and potent macrocyclic pyrrolopyrimidines as MerTK inhibitors using a structure-based approach. The most active macrocycles had an EC50 below 40 nM in a cell-based MerTK phosphor-protein ELISA assay. The X-ray structure of macrocyclic analogue 3 complexed with MerTK was also resolved and demonstrated macrocycles binding in the ATP binding pocket of the MerTK protein as anticipated. In addition, the lead compound 16 (UNC3133) had a 1.6 h half-life and 16% oral bioavailability in a mouse PK study.

  13. [Cytotoxicity of chimera peptides incorporating sequences of cyclin kinases inhibitors].

    PubMed

    Kharchenko, V P; Kulinich, V G; Lunin, V G; Filiasova, E I; Shishkin, A M; Sergeenko, O V; Riazanova, E M; Voronina, O L; Bozhenko, V K

    2007-01-01

    The study is concerned with proapoptotic properties of chimera peptides which incorporate sequences of inhibitors of cyclin kinases p161NK4a and p21CIP/WAF1 as well as internalized sequences (Antp and tat). Sequences of the p16 type appeared to be more cytotoxic than the p21 one. Cytotoxic effect proved dependent on orientation with respect to the C or N terminal point of a polypeptide chain rather than on chimera sequence extent. Although p16 endogenous synthesis did not influence chimera peptide levels, apoptosis did not take place in certain cellular lines. Due to the rather unsophisticated nature of such synthesis, it might be used in designing individually-tailored chemotherapeutic drugs.

  14. Mechanisms of resistance to EGFR tyrosine kinase inhibitors

    PubMed Central

    Huang, Lihua; Fu, Liwu

    2015-01-01

    Since the discovery that non-small cell lung cancer (NSCLC) is driven by epidermal growth factor receptor (EGFR) mutations, the EGFR tyrosine kinase inhibitors (EGFR-TKIs, e.g., gefitinib and elrotinib) have been effectively used for clinical treatment. However, patients eventually develop drug resistance. Resistance to EGFR-TKIs is inevitable due to various mechanisms, such as the secondary mutation (T790M), activation of alternative pathways (c-Met, HGF, AXL), aberrance of the downstream pathways (K-RAS mutations, loss of PTEN), impairment of the EGFR-TKIs-mediated apoptosis pathway (BCL2-like 11/BIM deletion polymorphism), histologic transformation, ATP binding cassette (ABC) transporter effusion, etc. Here we review and summarize the known resistant mechanisms to EGFR-TKIs and provide potential targets for development of new therapeutic strategies. PMID:26579470

  15. A matched couple: Combining kinase inhibitors with immunotherapy for cancer treatment.

    PubMed

    Jiang, Qun; Weiss, Jonathan M; Wiltrout, Robert H

    2012-01-01

    Small-molecule kinase inhibitors targeting oncogenic signaling pathways have been explored as cancer therapeutic agents due to their strong anti-tumor activity and manageable toxicity. Accumulating evidence shows that many kinase inhibitors also profoundly modulate immune cell functions, suggesting they may be promising candidates for combination with immunotherapeutic agents for the improved treatment of cancer.

  16. Aurora Kinases and Potential Medical Applications of Aurora Kinase Inhibitors: A Review

    PubMed Central

    Gavriilidis, Paschalis; Giakoustidis, Alexandros; Giakoustidis, Dimitrios

    2015-01-01

    Aurora kinases (AKs) represent a novel group of serine/threonine kinases. They were originally described in 1995 by David Glover in the course of studies of mutant alleles characterized with unusual spindle pole configuration in Drosophila melanogaster. Thus far, three AKs A, B, and C have been discovered in human healthy and neoplastic cells. Each one locates in different subcellular locations and they are all nuclear proteins. AKs are playing an essential role in mitotic events such as monitoring of the mitotic checkpoint, creation of bipolar mitotic spindle and alignment of centrosomes on it, also regulating centrosome separation, bio-orientation of chromosomes and cytokinesis. Any inactivation of them can have catastrophic consequences on mitotic events of spindle formation, alignment of centrosomes and cytokinesis, resulting in apoptosis. Overexpression of AKs has been detected in diverse solid and hematological cancers and has been linked with a dismal prognosis. After discovery and identification of the first aurora kinase inhibitor (AKI) ZM447439 as a potential drug for targeted therapy in cancer treatment, approximately 30 AKIs have been introduced in cancer treatment. PMID:26345296

  17. Aurora Kinase Inhibitors in Oncology Clinical Trials: Current State of the Progress.

    PubMed

    Falchook, Gerald S; Bastida, Christel C; Kurzrock, Razelle

    2015-12-01

    The Aurora kinase family of kinases (Aurora A, B, and C) are involved in multiple mitotic events, and aberrant expression of these kinases is associated with tumorigenesis. Aurora A and Aurora B are validated anticancer targets, and the development of Aurora kinase inhibitors has progressed from preclinical to clinical studies. A variety of Aurora A, B and pan-Aurora kinase inhibitors have entered the clinic. The main side effects include febrile neutropenia, stomatitis, gastrointestinal toxicity, hypertension, and fatigue. Responses including complete remissions have been described in diverse, advanced malignancies, most notably ovarian cancer and acute myelogenous leukemia. This review highlights the biologic rationale for Aurora kinase as a target, and clinical trials involving Aurora kinase inhibitors, with particular emphasis on published early phase studies, and the observed anti-tumor activity of these agents.

  18. Affinity purification of proteins binding to kinase inhibitors immobilized on self-assembling monolayers.

    PubMed

    Bantscheff, Marcus; Hobson, Scott; Kuster, Bernhard

    2012-01-01

    Kinase inhibitors represent a relatively new class of drugs that offer novel therapies targeting specific -malfunctioning kinase-mediated signaling pathways in oncology and potentially inflammation. As the ATP binding sites of the ∼500 human kinases are structurally conserved and because most current drugs target the ATP binding site, there is a need to profile all the kinases that a drug may bind and/or inhibit. We have developed a chemical proteomics method that affinity purifies kinases from cell or tissue lysates using kinase inhibitors immobilized on self-assembling monolayers. The method can be applied to assess the selectivity of a given kinase inhibitor and thus to guide its preclinical or clinical development.

  19. A mitogen-activated protein kinase kinase inhibitor induced compound skin toxicity with oedema in metastatic malignant melanoma.

    PubMed

    Thomas, C L; Mortimer, P S; Larkin, J M; Basu, T N; Gore, M E; Fearfield, L

    2016-04-01

    We report three cases of skin toxicity associated with oral mitogen-activated protein kinase kinase (MEK) inhibitor treatment for metastatic malignant melanoma (MM). All three patients developed oedema, and a single patient experienced eyelash trichomegaly. This is the first known report of eyelash trichomegaly secondary to MEK inhibitor use. We also discuss possible mechanisms for MEK inhibitor-associated oedema development. This series supports the role of the dermatologist in the screening and management of patients in the rapidly developing oncology setting, as new targeted agents can give rise to marked skin toxicity.

  20. The cyclin-dependent kinase (CDK) inhibitor flavopiridol inhibits glycogen phosphorylase.

    PubMed

    Kaiser, A; Nishi, K; Gorin, F A; Walsh, D A; Bradbury, E M; Schnier, J B

    2001-02-15

    Flavopiridol has been shown to induce cell cycle arrest and apoptosis in various tumor cells in vitro and in vivo. Using immobilized flavopiridol, we identified glycogen phosphorylases (GP) from liver and brain as flavopiridol binding proteins from HeLa cell extract. Purified rabbit muscle GP also bound to the flavopiridol affinity column. GP is the rate-limiting enzyme in intracellular glycogen breakdown. Flavopiridol significantly inhibited the AMP-activated GP-b form of the purified rabbit muscle isoenzyme (IC50 of 1 microM at 0.8 mM AMP), but was less inhibitory to the active phosphorylated form of GP, GP-a (IC50 of 2.5 microM). The AMP-bound GP-a form was poorly inhibited by flavopiridol (40% at 10 microM). Increasing concentrations of the allosteric effector AMP resulted in a linear decrease in the GP-inhibitory activity of flavopiridol suggesting interference between flavopiridol and AMP. In contrast the GP inhibitor caffeine had no effect on the relative GP inhibition by flavopiridol, suggesting an additive effect of caffeine. Flavopiridol also inhibited the phosphorylase kinase-catalyzed phosphorylation of GP-b by inhibiting the kinase in vitro. Flavopiridol thus is able to interfere with both activating modifications of GP-b, AMP activation and phosphorylation. In A549 NSCLC cells flavopiridol treatment caused glycogen accumulation despite of an increase in GP activity, suggesting direct GP inhibition in vivo rather than inhibition of GP activation by phosphorylase kinase. These results suggest that the cyclin-dependent kinase inhibitor flavopiridol interferes with glycogen degradation, which may be responsible for flavopiridol's cytotoxicity and explain its resistance in some cell lines.

  1. Combined effects of PI3K and SRC kinase inhibitors with imatinib on intracellular calcium levels, autophagy, and apoptosis in CML-PBL cells.

    PubMed

    Ciarcia, Roberto; Damiano, Sara; Montagnaro, Serena; Pagnini, Ugo; Ruocco, Antonio; Caparrotti, Giuseppe; d'Angelo, Danila; Boffo, Silvia; Morales, Fátima; Rizzolio, Flavio; Florio, Salvatore; Giordano, Antonio

    2013-09-01

    Imatinib induces a complete cytogenetic regression in a large percentage of patients affected by chronic myeloid leukemia (CML) until mutations in the kinase domain of BCR-ABL appear. Alternative strategies for CML patients include the inhibition of phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway, which is constitutively activated in leukemia cells and seems important for the regulation of cell proliferation, viability, and autophagy. In this study, we verified the effect of imatinib mesylate (IM), alone or in association with LY294002 (LY) (a specific PI3K protein tyrosine kinase inhibitor) or 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]-pyrimidine (PP1) (a Src tyrosine kinase inhibitor), on viability, intracellular calcium mobilization, apoptosis, and autophagy, in order to verify possible mechanisms of interaction. Our data demonstrated that PP1 and LY interact synergistically with IM by inducing apoptosis and autophagy in Bcr/Abl+ leukemia cells and this mechanism is related to the stress of the endoplasmic reticulum (ER). Our findings suggest a reasonable relationship between apoptotic and autophagic activity of tyrosine kinase inhibitors (TKIs) and the functionality of smooth ER Ca (2+)-ATPase and inositol triphosphate receptors, independently of intracellular calcium levels. Therapeutic strategies combining imatinib with PI3K and/or Src kinase inhibitors warrant further investigations in Bcr/Abl+ malignancies, particularly in the cases of imatinib mesylate-resistant disease.

  2. Structure-based lead discovery for protein kinase C zeta inhibitor design by exploiting kinase-inhibitor complex crystal structure data and potential therapeutics for preterm labour.

    PubMed

    Shao, Qing-Chun; Zhang, Cui-Juan; Li, Jie

    2014-10-14

    The protein kinase C (PKC) is a family of serine/threonine kinases with a broad range of cellular targets. Members of the PKC family participate at the diverse biological events involved in cellular proliferation, differentiation and survival. The PKC isoform zeta (PKCζ) is an atypical member that has recently been found to play an essential role in promoting human uterine contractility and thus been raised as a new target for treating preterm labour and other tocolytic diseases. In this study, an integrative protocol was described to graft hundreds of inhibitor ligands from their complex crystal structures with cognate kinases into the active pocket of PKCζ and, based on the modeled structures, to evaluate the binding strength of these inhibitors to the non-cognate PKCζ receptor by using a consensus scoring strategy. A total of 32 inhibitors with top score were compiled, and eight out of them were tested for inhibitory potency against PKCζ. Consequently, five compounds, i.e. CDK6 inhibitor fisetin, PIM1 inhibitor myricetin, CDK9 inhibitor flavopiridol and PknB inhibitor mitoxantrone as well as the promiscuous kinase inhibitor staurosporine showed high or moderate inhibitory activity on PKCζ, with IC50 values of 58 ± 9, 1.7 ± 0.4, 108 ± 17, 280 ± 47 and 0.019 ± 0.004 μM, respectively, while other three compounds, including two marketed drugs dasatinib and sunitinib as well as the Rho inhibitor fasudil, have not been detected to possess observable activity. Next, based on the modeled structure data we modified three flavonoid kinase inhibitors, i.e. fisetin, myricetin and flavopiridol, to generate a number of more potential molecular entities, two of which were found to have a moderately improved activity as compared to their parent compounds.

  3. PF-114, a potent and selective inhibitor of native and mutated BCR/ABL is active against Philadelphia chromosome-positive (Ph+) leukemias harboring the T315I mutation.

    PubMed

    Mian, A A; Rafiei, A; Haberbosch, I; Zeifman, A; Titov, I; Stroylov, V; Metodieva, A; Stroganov, O; Novikov, F; Brill, B; Chilov, G; Hoelzer, D; Ottmann, O G; Ruthardt, M

    2015-05-01

    Targeting BCR/ABL with tyrosine kinase inhibitors (TKIs) is a proven concept for the treatment of Philadelphia chromosome-positive (Ph+) leukemias. Resistance attributable to either kinase mutations in BCR/ABL or nonmutational mechanisms remains the major clinical challenge. With the exception of ponatinib, all approved TKIs are unable to inhibit the 'gatekeeper' mutation T315I. However, a broad spectrum of kinase inhibition increases the off-target effects of TKIs and may be responsible for cardiovascular issues of ponatinib. Thus, there is a need for more selective options for the treatment of resistant Ph+ leukemias. PF-114 is a novel TKI developed with the specifications of (i) targeting T315I and other resistance mutations in BCR/ABL; (ii) achieving a high selectivity to improve safety; and (iii) overcoming nonmutational resistance in Ph+ leukemias. PF-114 inhibited BCR/ABL and clinically important mutants including T315I at nanomolar concentrations. It suppressed primary Ph+ acute lymphatic leukemia-derived long-term cultures that either displayed nonmutational resistance or harbor the T315I. In BCR/ABL- or BCR/ABL-T315I-driven murine leukemia as well as in xenograft models of primary Ph+ leukemia harboring the T315I, PF-114 significantly prolonged survival to a similar extent as ponatinib. Our work supports clinical evaluation of PF-114 for the treatment of resistant Ph+ leukemia.

  4. Rho-kinase inhibitor Y-27632 increases cellular proliferation and migration in human foreskin fibroblast cells.

    PubMed

    Piltti, Juha; Varjosalo, Markku; Qu, Chengjuan; Häyrinen, Jukka; Lammi, Mikko J

    2015-09-01

    The idea of direct differentiation of somatic cells into other differentiated cell types has attracted a great interest recently. Rho-kinase inhibitor Y-27632 (ROCKi) is a potential drug molecule, which has been reported to support the gene expressions typical for the chondrocytes, thus restricting their phenotypic conversion to fibroblastic cells upon the cellular expansion. In this study, we have investigated the short-term biological responses of ROCKi to human primary foreskin fibroblasts. The fibroblast cells were exposed to 1 and 10 μM ROCKi treatments. A proteomics analysis revealed expression changes of 56 proteins, and a further protein pathway analysis suggested their association with the cell morphology, the organization, and the increased cellular movement and the proliferation. These functional responses were confirmed by a Cell-IQ time-lapse imaging analysis. Rho-kinase inhibitor treatment increased the cellular proliferation up to twofold during the first 12 h, and a wound model based migration assay showed 50% faster filling of the mechanically generated wound area. Additionally, significantly less vinculin-associated focal adhesions were present in the ROCKi-treated cells. Despite the marked changes in the cell behavior, ROCKi was not able to induce the expression of the chondrocyte-specific genes, such as procollagen α1 (II) and aggrecan.

  5. A chemoproteomic method for identifying cellular targets of covalent kinase inhibitors

    PubMed Central

    Chen, Ying-Chu; Zhang, Chao

    2016-01-01

    Protein kinases are attractive drug targets for numerous human diseases including cancers, diabetes and neurodegeneration. A number of kinase inhibitors that covalently target a cysteine residue in their target kinases have recently entered use in the cancer clinic. Despite the advantages of covalent kinases inhibitors, their inherent reactivity can lead to non-specific binding to other cellular proteins and cause off- target effects in cells. It is thus essential to determine the identity of these off targets in order to fully account for the phenotype and to improve the selectivity and efficacy of covalent inhibitors. Herein we present a detailed protocol for a chemoproteomic method to enrich and identify cellular targets of covalent kinase inhibitors. PMID:27551330

  6. Bisubstrate fluorescent probes and biosensors in binding assays for HTS of protein kinase inhibitors.

    PubMed

    Uri, Asko; Lust, Marje; Vaasa, Angela; Lavogina, Darja; Viht, Kaido; Enkvist, Erki

    2010-03-01

    Conjugates of adenosine mimics and d-arginine-rich peptides (ARCs) are potent inhibitors of protein kinases (PKs) from the AGC group. Labeling ARCs with fluorescent dyes or immobilizing on chip surfaces gives fluorescent probes (ARC-Photo) and biosensors that can be used for high-throughput screening (HTS) of inhibitors of protein kinases. The bisubstrate character (simultaneous association with both binding sites of the kinase) and high affinity of ARCs allow ARC-based probes and sensors to be used for characterization of inhibitors targeted to either binding site of the kinase with affinities in whole nanomolar to micromolar range. The ability to penetrate cell plasma membrane and bind to the target kinase fused with a fluorescent protein leads to the possibility to use ARC-Photo probes for high content screening (HCS) of inhibitors in cellular milieu with detection of intensity of Förster resonance energy transfer (FRET) between two fluorophores.

  7. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton

    SciTech Connect

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A.; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A.

    2013-08-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness. -Highlights: • Each of the eight Arg isoforms was transfected in COS-7 cells. • Only the 1BSCTS Arg isoform has a nuclear distribution in transfected cells. • The cytoplasmic isoforms and F-actin colocalize cortically and in cell protrusions. • Arg isoforms differently phosphorylate p190RhoGAP and CrkII. • Arg isoforms differently modulate stress fibers, cell protrusions and motility.

  8. Kinase inhibitors as potential therapeutics for acute and chronic neurodegenerative conditions.

    PubMed

    Cuny, G D

    2009-01-01

    Kinases, which number > 500 in humans, are a class of enzymes that participate in an array of important functions within normal cellular physiology and during various pathological conditions. Due to the key role of kinases in the regulation of all aspects of cellular signaling and the well established contribution of kinase dysregulation to the etiology of many human pathologies, the development of kinase inhibitors has emerged as a therapeutic strategy for the treatment of human disease, including most notably oncology. Difficulties generating selective inhibitors have hampered their use in other therapeutic areas with less tolerance for off-target effects. However, with an increasing understanding of kinase structures and with the advent of newer inhibitor design strategies more highly selective inhibitors are beginning to emerge. This has prompted interest in utilizing kinase inhibitors in therapeutic areas beyond oncology, including acute and chronic neurodegenerative conditions for which disease modify therapies are lacking. This review provides a background in acute (i.e. brain ischemia and traumatic brain injury) and chronic (i.e. Alzheimer's, Parkinson's, Huntington's disease, amyotrophic lateral sclerosis and multiple sclerosis) neurodegenerative conditions. Then, the role of several kinase (i.e. JNK3, p38 MAPK, ERK, PKC, ROCKII, GSK3, Cdk5, MLK, EphB3 kinase, RIP1 kinase, LRRK2, TTBK1, ASK1, CK, DAPK, and PKN1) that could serve as potential therapeutic targets for these maladies are reviewed.

  9. Novel mutant-selective EGFR kinase inhibitors against EGFR T790M

    SciTech Connect

    Zhou, Wenjun; Ercan, Dalia; Chen, Liang; Yun, Cai-Hong; Li, Danan; Capelletti, Marzia; Cortot, Alexis B.; Chirieac, Lucian; Iacob, Roxana E.; Padera, Robert; Engen, John R.; Wong, Kwok-Kin; Eck, Michael J.; Gray, Nathanael S.; Jänne, Pasi A.

    2010-01-12

    The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors in EGFR-mutant non-small-cell lung cancer (NSCLC) is limited by the development of drug-resistance mutations, including the gatekeeper T790M mutation. Strategies targeting EGFR T790M with irreversible inhibitors have had limited success and are associated with toxicity due to concurrent inhibition of wild-type EGFR. All current EGFR inhibitors possess a structurally related quinazoline-based core scaffold and were identified as ATP-competitive inhibitors of wild-type EGFR. Here we identify a covalent pyrimidine EGFR inhibitor by screening an irreversible kinase inhibitor library specifically against EGFR T790M. These agents are 30- to 100-fold more potent against EGFR T790M, and up to 100-fold less potent against wild-type EGFR, than quinazoline-based EGFR inhibitors in vitro. They are also effective in murine models of lung cancer driven by EGFR T790M. Co-crystallization studies reveal a structural basis for the increased potency and mutant selectivity of these agents. These mutant-selective irreversible EGFR kinase inhibitors may be clinically more effective and better tolerated than quinazoline-based inhibitors. Our findings demonstrate that functional pharmacological screens against clinically important mutant kinases represent a powerful strategy to identify new classes of mutant-selective kinase inhibitors.

  10. Feasibility of using molecular docking-based virtual screening for searching dual target kinase inhibitors.

    PubMed

    Zhou, Shunye; Li, Youyong; Hou, Tingjun

    2013-04-22

    Multitarget agents have been extensively explored for solving limited efficacies, poor safety, and resistant profiles of an individual target. Theoretical approaches for searching and designing multitarget agents are critically useful. Here, the performance of molecular docking to search dual-target inhibitors for four kinase pairs (CDK2-GSK3B, EGFR-Src, Lck-Src, and Lck-VEGFR2) was assessed. First, the representative structures for each kinase target were chosen by structural clustering of available crystal structures. Next, the performance of molecular docking to distinguish inhibitors from noninhibitors for each individual kinase target was evaluated. The results show that molecular docking-based virtual screening illustrates good capability to find known inhibitors for individual targets, but the prediction accuracy is structurally dependent. Finally, the performance of molecular docking to identify the dual-target kinase inhibitors for four kinase pairs was evaluated. The analyses show that molecular docking successfully filters out most noninhibitors and achieves promising performance for identifying dual-kinase inhibitors for CDK2-GSK3B and Lck-VEGFR2. But a high false-positive rate leads to low enrichment of true dual-target inhibitors in the final list. This study suggests that molecular docking serves as a useful tool in searching inhibitors against dual or even multiple kinase targets, but integration with other virtual screening tools is necessary for achieving better predictions.

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

    SciTech Connect

    Tamm, Christoffer Galito, Sara Pijuan Anneren, Cecilia

    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.

  12. Screening of Microbial Extracts for Anticancer Compounds Using Streptomyces Kinase Inhibitor Assay.

    PubMed

    Shanbhag, Prashant; Bhave, Sarita; Vartak, Ashwini; Kulkarni-Almeida, Asha; Mahajan, Girish; Villanueva, Ivan; Davies, Julian

    2015-07-01

    Eukaryotic kinases are known to play an important role in signal transduction pathways by phosphorylating their respective substrates. Abnormal phosphorylations by these kinases have resulted in diseases. Hence inhibitors of kinases are of considerable pharmaceutical interest for a wide variety of disease targets, especially cancers. A number of reports have been published which indicate that eukaryotic-like kinases may complement two-component kinase systems in several bacteria. In Streptomyces sp. such kinases have been found to have a role in formation of aerial hyphae, spores, pigmentation & even in antibiotic production in some strains. Eukaryotic kinase inhibitors are seen to inhibit formation of aerial mycelia in Streptomyces without inhibiting vegetative mycelia. This property has been used to design an assay to screen for eukaryotic kinase inhibitors. The assay involves testing of compounds against Streptomyces 85E ATCC 55824 using agar well diffusion method. Inhibitors of kinases give rise to "bald" colonies where aerial mycelia and sporulation inhibition is seen. The assay has been standardized using known eukaryotic protein kinase inhibiting anticancer agents like AG-490, AG-1295, AG-1478, Flavopiridol and Imatinib as positive controls, at a concentration ranging from 10 μg/well to 100 μg/well. Anti-infective compounds which are not reported to inhibit eukaryotic protein kinases were used as negative controls. A number of microbial cultures have been screened for novel eukaryotic protein kinase inhibitors. Further these microbial extracts were tested in various cancer cell lines like Panel, HCT116, Calul, ACHN and H460 at a concentration of 10 μg/mL/ well. The anticancer data was seen correlating well with the Streptomyces kinase assay thus validating the assay.

  13. Antagonism of SET using OP449 enhances the efficacy of tyrosine kinase inhibitors and overcome drug resistance in myeloid leukemia

    PubMed Central

    Agarwal, Anupriya; MacKenzie, Ryan J.; Pippa, Raffaella; Eide, Christopher A.; Oddo, Jessica; Tyner, Jeffrey W.; Sears, Rosalie; Vitek, Michael P.; Odero, María D.; Christensen, Dale; Druker, Brian J.

    2014-01-01

    Purpose The SET oncoprotein, a potent inhibitor of the protein phosphatase 2A (PP2A), is overexpressed in leukemia. We evaluated the efficacy of SET antagonism in chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) cell lines, a murine leukemia model, and primary patient samples using OP449, a specific, cell-penetrating peptide that antagonizes SET's inhibition of PP2A. Experimental Design In vitro cytotoxicity and specificity of OP449 in CML and AML cell lines and primary samples were measured using proliferation, apoptosis and colonogenic assays. Efficacy of target inhibition by OP449 is evaluated by immunoblotting and PP2A assay. In vivo antitumor efficacy of OP449 was measured in human HL-60 xenografted murine model. Results We observed that OP449 inhibited growth of CML cells including those from patients with blastic phase disease and patients harboring highly drug-resistant BCR-ABL1 mutations. Combined treatment with OP449 and ABL1 tyrosine kinase inhibitors was significantly more cytotoxic to K562 cells and primary CD34+ CML cells. SET protein levels remained unchanged with OP449 treatment, but BCR-ABL1-mediated downstream signaling was significantly inhibited with the degradation of key signaling molecules such as BCR-ABL1, STAT5, and AKT. Similarly, AML cell lines and primary patient samples with various genetic lesions showed inhibition of cell growth after treatment with OP449 alone or in combination with respective kinase inhibitors. Finally, OP449 reduced the tumor burden of mice xenografted with human leukemia cells. Conclusions We demonstrate a novel therapeutic paradigm of SET antagonism using OP449 in combination with tyrosine kinase inhibitors for the treatment of CML and AML. PMID:24436473

  14. Tyrosine Kinase Inhibitors as Initial Therapy for Patients with Chronic Myeloid Leukemia in Accelerated Phase

    PubMed Central

    Ohanian, Maro; Kantarjian, Hagop M.; Quintas-Cardama, Alfonso; Jabbour, Elias; Abruzzo, Lynne; Verstovsek, Srdan; Borthakur, Gautam; Ravandi, Farhad; Garcia-Manero, Guillermo; Champlin, Richard; Pierce, Sherry; Alattar, Mona Lisa; Trinh, Long Xuan; Luthra, Raja; Ferrajoli, Alessandra; Kadia, Tapan; O’Brien, Susan; Cortes, Jorge E.

    2013-01-01

    Background Accelerated phase CML (CML-AP) most frequently represents a progression state in CML. However, some patients present with AP features at the time of diagnosis. There is limited information on the outcome of these patients when receiving tyrosine kinase inhibitors (TKI) as initial therapy. Methods We analyzed the outcome of 51 consecutive patients with CML who presented with features of AP at the time of diagnosis, including blasts ≥15% (n=6), basophils ≥20%, (n=22), platelets <100×109/L (n=3), cytogenetic clonal evolution (n=17), or more than 1 feature (n=3). Patients received initial therapy with imatinib (n=30), dasatinib (n=5) or nilotinib (n=16). Results The rate of complete cytogenetic response (CCyR) for patients treated with imatinib was 80%, and with dasatinib or nilotinib was 90%. Major molecular response (MMR, BCR-ABL/ABL ≤0.1%, by International Scale [IS]) was achieved in 69% including complete molecular responses (MR4.5, BCR-ABL/ABL ≤0.0032% IS) in 49%. MMR rates for patients treated with imatinib were 63%, and with second generation TKI (2GTKIs) 76%. Overall survival at 36 months was 87% with imatinib and 95% with 2GTKI’s. Conclusion TKIs should be considered standard initial therapy for patients with AP at the time of diagnosis. PMID:24332214

  15. Design, synthesis, and biological evaluation of 3-(1H-1,2,3-triazol-1-yl)benzamide derivatives as Potent Pan Bcr-Abl inhibitors including the threonine(315)→isoleucine(315) mutant.

    PubMed

    Li, Yupeng; Shen, Mengjie; Zhang, Zhang; Luo, Jinfeng; Pan, Xiaofen; Lu, Xiaoyun; Long, Huoyou; Wen, Donghai; Zhang, Fengxiang; Leng, Fang; Li, Yingjun; Tu, Zhengchao; Ren, Xiaomei; Ding, Ke

    2012-11-26

    A series of 3-(1H-1,2,3-triazol-1-yl)benzamide derivatives were designed and synthesized as new Bcr-Abl inhibitors by using combinational strategies of bioisosteric replacement, scaffold hopping, and conformational constraint. The compounds displayed significant inhibition against a broad spectrum of Bcr-Abl mutants including the gatekeeper T315I and p-loop mutations, which are associated with disease progression in CML. The most potent compounds 6q and 6qo strongly inhibited the kinase activities of Bcr-Abl(WT) and Bcr-Abl(T315I) with IC(50) values of 0.60, 0.36 and 1.12, 0.98 nM, respectively. They also potently suppressed the proliferation of K562, KU812 human CML cells, and a panel of murine Ba/F3 cells ectopically expressing either Bcr-Abl(WT) or any of a panel of other Bcr-Abl mutants that have been shown to contribute to clinical acquired resistance, including Bcr-Abl(T315I), with IC(50) values in low nanomolar ranges. These compounds may serve as lead compounds for further development of new Bcr-Abl inhibitors capable of overcoming clinical acquired resistance against imatinib.

  16. Have adjuvant tyrosine kinase inhibitors lost their shine?

    PubMed Central

    Sabari, Joshua K.

    2016-01-01

    Despite broad advances in molecularly targeted therapies, lung cancer remains the leading cause of cancer related mortality in the United States. Epidermal growth factor receptor (EGFR) mutations occur in approximately 17% of advanced non-small cell lung cancer (NSCLC) in the US population. The remarkable efficacy of small-molecule EGFR tyrosine kinase inhibitors (TKIs) in this unique subset of patients has revolutionized the therapeutic approach to lung cancer. The success of these agents in the metastatic setting leads to the logical question of what role these drugs may have in the adjuvant setting for patients with earlier stage disease. RADIANT, an international randomized, double-blind, placebo controlled phase III study in patients with completely resected stage IB to IIIA NSLC whose tumors expressed EGFR by IHC and EGFR amplification by FISH, attempted to answer the question of whether erlotinib would improve disease free survival and overall survival in the adjuvant setting. While RADIANT does not conclude for or against adjuvant use of EGFR-TKIs, all data points towards benefit in a selected population. As clinicians, we must continue to enroll to potentially practice changing therapeutic neoadjuvant and adjuvant chemotherapy studies internationally. PMID:27568486

  17. Fluorescent biosensors for high throughput screening of protein kinase inhibitors.

    PubMed

    Prével, Camille; Pellerano, Morgan; Van, Thi Nhu Ngoc; Morris, May C

    2014-02-01

    High throughput screening assays aim to identify small molecules that interfere with protein function, activity, or conformation, which can serve as effective tools for chemical biology studies of targets involved in physiological processes or pathways of interest or disease models, as well as templates for development of therapeutics in medicinal chemistry. Fluorescent biosensors constitute attractive and powerful tools for drug discovery programs, from high throughput screening assays, to postscreen characterization of hits, optimization of lead compounds, and preclinical evaluation of candidate drugs. They provide a means of screening for inhibitors that selectively target enzymatic activity, conformation, and/or function in vitro. Moreover, fluorescent biosensors constitute useful tools for cell- and image-based, multiplex and multiparametric, high-content screening. Application of fluorescence-based sensors to screen large and complex libraries of compounds in vitro, in cell-based formats or whole organisms requires several levels of optimization to establish robust and reproducible assays. In this review, we describe the different fluorescent biosensor technologies which have been applied to high throughput screens, and discuss the prerequisite criteria underlying their successful application. Special emphasis is placed on protein kinase biosensors, since these enzymes constitute one of the most important classes of therapeutic targets in drug discovery.

  18. Anti-Inflammatory Effects of Protein Kinase Inhibitor Pyrrol Derivate

    PubMed Central

    Yena, Maryna S.; Kotlyar, Iryna P.; Ogloblya, Olexandr V.; Rybalchenko, Volodymyr K.

    2016-01-01

    In our previous studies we showed antitumor and anti-inflammatory activities of protein kinases inhibitor pyrrol derivate 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2,5-dione (MI-1) on rat colon cancer model. Therefore anti-inflammatory effect of MI-1 on rat acetic acid induced ulcerative colitis (UC) model was aimed to be discovered. The anti-inflammatory effects of MI-1 (2.7 mg/kg daily) compared to reference drug Prednisolone (0.7 mg/kg daily) after 14-day usage were evaluated on macro- and light microscopy levels and expressed in 21-grade scale. Redox status of bowel mucosa was also estimated. It was shown that in UC group the grade of total injury (GTI) was equal to 9.6 (GTIcontrol = 0). Increase of malonic dialdehyde (MDA) by 89% and protein carbonyl groups (PCG) by 60% and decrease of superoxide dismutase (SOD) by 40% were also observed. Prednisolone decreased GTI to 3 and leveled SOD activity, but MDA and PCG remained higher than control ones by 52% and 42%, respectively. MI-1 restored colon mucosa integrity and decreased mucosa inflammation down to GTI = 0.5 and leveled PCG and SOD. Thus, MI-1 possessed anti-inflammatory properties, which were more expressed that Prednisolone ones, as well as normalized mucosa redox balance, and so has a prospect for correction of inflammatory processes. PMID:28101521

  19. Kinase inhibitors and monoclonal antibodies in oncology: clinical implications.

    PubMed

    Gharwan, Helen; Groninger, Hunter

    2016-04-01

    Molecularly targeted cancer therapies, such as small-molecule kinase inhibitors and monoclonal antibodies, constitute a rapidly growing and an important part of the oncology armamentarium. Unlike conventional (cytotoxic) chemotherapeutics, targeted therapies were designed to disrupt cancer cell pathogenesis at specific biological points essential for the development and progression of the tumour. These agents were developed to disrupt specific targets with the aim of minimizing treatment burden compared with conventional chemotherapy. Nevertheless the increasingly common use of targeted therapies has revealed some unanticipated, often clinically significant toxic effects, as well as compromising effective palliative and end-of-life management approaches. Although patients and clinicians welcome improvements in cancer prognosis, these changes can also impact patient quality-of-life. Therefore, as demand for oncology expertise increases, physicians need to apprise themselves of targeted therapies and their clinical implications, including drug-specific side effects, impact on quality of life, and cost issues, especially in relation to end-of-life care. This Review provides a useful summary and guide for professionals treating patients with malignant diseases.

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

    SciTech Connect

    Tesmer, John J.G.; Tesmer, Valerie M.; Lodowski, David T.; Steinhagen, Henning; Huber, Jochen

    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.

  1. Regulation of the activity of protein kinases by endogenous heat stable protein inhibitors.

    PubMed

    Szmigielski, A

    1985-01-01

    Protein kinase activities are regulated by endogenous thermostable protein inhibitors. Type I inhibitor is a protein of MW 22,000-24,000 which inhibits specifically cyclic AMP-(cAMP) dependent protein kinase (APK) as a competitive inhibitor of catalytic subunits of the enzyme. Type I inhibitor activity changes inversely according to the activation of adenylate cyclase and the changes in cAMP content in tissues. It seems that type I inhibitor serves as a factor preventing spontaneous cAMP-dependent phosphorylation in unstimulated cell. The other thermostable protein which inhibits APK activity has been found in Sertoli cell-enriched testis (testis inhibitor). Physiological role of the testis inhibitor is unknown. Type II inhibitor is a protein of MW 15,000 which blocks phosphorylation mediated by cAMP and cyclic GMP (cGMP) dependent (APK and GPK) and cyclic nucleotide independent protein kinases as a competitive inhibitor of substrate proteins. Activity of this inhibitor specifically changes in reciprocal manner to the changes in cGMP content. It seems that type II inhibitor serves as a factor preventing the phosphorylation catalyzed by GPK when cGMP content is low. Stimulation of guanylate cyclase and activation of GPK is followed by a decrease of type II inhibitor activity. This change in relationship between activities of GPK and type II inhibitor allows for effective phosphorylation catalyzed by this enzyme when cGMP content is increased.

  2. A roadmap to evaluate the proteome-wide selectivity of covalent kinase inhibitors

    PubMed Central

    Dix, Melissa M.; Douhan, John; Gilbert, Adam M.; Hett, Erik C.; Johnson, Theodore O.; Joslyn, Chris; Kath, John C.; Niessen, Sherry; Roberts, Lee R.; Schnute, Mark E.; Wang, Chu; Hulce, Jonathan J.; Wei, Baoxian; Whiteley, Laurence O.; Hayward, Matthew M.; Cravatt, Benjamin F.

    2014-01-01

    Kinases are principal components of signal transduction pathways and the focus of intense basic and drug discovery research. Irreversible inhibitors that covalently modify non-catalytic cysteines in kinase active-sites have emerged as valuable probes and approved drugs. Many protein classes, however, possess functional cysteines and therefore understanding the proteome-wide selectivity of covalent kinase inhibitors is imperative. Here, we accomplish this objective using activity-based protein profiling coupled with quantitative mass spectrometry to globally map the targets, both specific and non-specific, of covalent kinase inhibitors in human cells. Many of the specific off-targets represent non-kinase proteins that, interestingly, possess conserved, active-site cysteines. We define windows of selectivity for covalent kinase inhibitors and show that, when these windows are exceeded, rampant proteome-wide reactivity and kinase target-independent cell death conjointly occur. Our findings, taken together, provide an experimental roadmap to illuminate opportunities and surmount challenges for the development of covalent kinase inhibitors. PMID:25038787

  3. Pim kinases modulate resistance to FLT3 tyrosine kinase inhibitors in FLT3-ITD acute myeloid leukemia

    PubMed Central

    Green, Alexa S.; Maciel, Thiago T.; Hospital, Marie-Anne; Yin, Chae; Mazed, Fetta; Townsend, Elizabeth C.; Pilorge, Sylvain; Lambert, Mireille; Paubelle, Etienne; Jacquel, Arnaud; Zylbersztejn, Florence; Decroocq, Justine; Poulain, Laury; Sujobert, Pierre; Jacque, Nathalie; Adam, Kevin; So, Jason C. C.; Kosmider, Olivier; Auberger, Patrick; Hermine, Olivier; Weinstock, David M.; Lacombe, Catherine; Mayeux, Patrick; Vanasse, Gary J.; Leung, Anskar Y.; Moura, Ivan C.; Bouscary, Didier; Tamburini, Jerome

    2015-01-01

    ABSTRACT Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) is frequently detected in acute myeloid leukemia (AML) patients and is associated with a dismal long-term prognosis. FLT3 tyrosine kinase inhibitors provide short-term disease control, but relapse invariably occurs within months. Pim protein kinases are oncogenic FLT3-ITD targets expressed in AML cells. We show that increased Pim kinase expression is found in relapse samples from AML patients treated with FLT3 inhibitors. Ectopic Pim-2 expression induces resistance to FLT3 inhibition in both FLT3-ITD–induced myeloproliferative neoplasm and AML models in mice. Strikingly, we found that Pim kinases govern FLT3-ITD signaling and that their pharmacological or genetic inhibition restores cell sensitivity to FLT3 inhibitors. Finally, dual inhibition of FLT3 and Pim kinases eradicates FLT3-ITD+ cells including primary AML cells. Concomitant Pim and FLT3 inhibition represents a promising new avenue for AML therapy. PMID:26601252

  4. The cyclin-dependent kinase inhibitor AT7519 accelerates neutrophil apoptosis in sepsis-related acute respiratory distress syndrome

    PubMed Central

    Felton, Jennifer M; Robb, Calum T; Craven, Thomas; Kipari, Tiina; Walsh, Timothy S; Haslett, Christopher; Kefala, Kallirroi; Rossi, Adriano G; Lucas, Christopher D

    2017-01-01

    Acute respiratory distress syndrome (ARDS) is a neutrophil-dominant disorder with no effective pharmacological therapies. While the cyclin-dependent kinase inhibitor AT7519 induces neutrophil apoptosis to promote inflammation resolution in preclinical models of lung inflammation, its potential efficacy in ARDS has not been examined. Untreated peripheral blood sepsis-related ARDS neutrophils demonstrated prolonged survival after 20 hours in vitro culture. AT7519 was able to override this phenotype to induce apoptosis in ARDS neutrophils with reduced expression of the pro-survival protein Mcl-1. We demonstrate the first pharmacological compound to induce neutrophil apoptosis in sepsis-related ARDS, highlighting cyclin-dependent kinase inhibitors as potential novel therapeutic agents. PMID:27965411

  5. Cyclin-dependent kinase inhibitors in maize endosperm and their potential role in endoreduplication.

    PubMed

    Coelho, Cintia M; Dante, Ricardo A; Sabelli, Paolo A; Sun, Yuejin; Dilkes, Brian P; Gordon-Kamm, William J; Larkins, Brian A

    2005-08-01

    Two maize (Zea mays) cyclin-dependent kinase (CDK) inhibitors, Zeama;KRP;1 and Zeama;KRP;2, were characterized and shown to be expressed in developing endosperm. Similar to the CDK inhibitors in Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum), the maize proteins contain a carboxy-terminal region related to the inhibitory domain of the mammalian Cip/Kip inhibitors. Zeama;KRP;1 is present in the endosperm between 7 and 21 d after pollination, a period that encompasses the onset of endoreduplication, while the Zeama;KRP;2 protein declines during this time. Nevertheless, Zeama;KRP;1 accounts for only part of the CDK inhibitory activity that peaks coincident with the endoreduplication phase of endosperm development. In vitro assays showed that Zeama;KRP;1 and Zeama;KRP;2 are able to inhibit endosperm Cdc2-related CKD activity that associates with p13(Suc1). They were also shown to specifically inhibit cyclin A1;3- and cyclin D5;1-associated CDK activities, but not cyclin B1;3/CDK. Overexpression of Zeama;KRP;1 in maize embryonic calli that ectopically expressed the wheat dwarf virus RepA protein, which counteracts retinoblastoma-related protein function, led to an additional round of DNA replication without nuclear division.

  6. Overcoming Resistance to HER2 Inhibitors Through State-Specific Kinase Binding

    PubMed Central

    Novotny, Chris J.; Pollari, Sirkku; Park, Jin H.; Lemmon, Mark A.; Shen, Weijun; Shokat, Kevan M.

    2016-01-01

    The heterodimeric receptor tyrosine kinase complex formed by HER2 and HER3 can act as an oncogenic driver and is also responsible for rescuing a large number of cancers from a diverse set of targeted therapies. Current inhibitors of these proteins, particularly HER2, have dramatically improved patient outcomes in the clinic but recent studies have demonstrated that stimulation of the heterodimeric complex, either by growth factors or increasing the concentrations of HER2 and HER3 at the membrane, significantly diminishes their activity. In order to find an inhibitor of the active HER2/HER3 oncogenic complex we developed a panel of Ba/F3 cell lines suitable for ultra-high throughput screening. Medicinal chemistry on the hit scaffold resulted in a novel inhibitor that acts through the preferential inhibition of the active state of HER2 and as a result is able to overcome cellular mechanisms of resistance such as growth factors or mutations that stabilize the active form of HER2. PMID:27595329

  7. Identification of small molecule inhibitors of phosphatidylinositol 3-kinase and autophagy.

    PubMed

    Farkas, Thomas; Daugaard, Mads; Jäättelä, Marja

    2011-11-11

    Macroautophagy (hereafter autophagy) is a lysosomal catabolic pathway that controls cellular homeostasis and survival. It has recently emerged as an attractive target for the treatment of a variety of degenerative diseases and cancer. The targeting of autophagy has, however, been hampered by the lack of specific small molecule inhibitors. Thus, we screened two small molecule kinase inhibitor libraries for inhibitors of rapamycin-induced autophagic flux. The three most potent inhibitors identified conferred profound inhibition of autophagic flux by inhibiting the formation of autophagosomes. Notably, the autophagy inhibitory effects of all three compounds were independent of their established kinase targets, i.e. ataxia telangiectasia mutated for KU55933, protein kinase C for Gö6976, and Janus kinase 3 for Jak3 inhibitor VI. Instead, we identified phosphatidylinositol 3-kinase (PtdIns3K) as a direct target of KU55933 and Gö6976. Importantly, and in contrast to the currently available inhibitors of autophagosome formation (e.g. 3-methyladenine), none of the three compounds inhibited the cell survival promoting class I phosphoinositide 3-kinase-Akt signaling at the concentrations required for effective autophagy inhibition. Accordingly, they proved to be valuable tools for investigations of autophagy-associated cell death and survival. Employing KU55399, we demonstrated that autophagy protects amino acid-starved cells against both apoptosis and necroptosis. Taken together, our data introduce new possibilities for the experimental study of autophagy and can form a basis for the development of clinically relevant autophagy inhibitors.

  8. Recent development of ATP-competitive small molecule phosphatidylinostitol-3-kinase inhibitors as anticancer agents

    PubMed Central

    Liu, Yu; Wan, Wen-zhu; Li, Yan; Zhou, Guan-lian; Liu, Xin-guang

    2017-01-01

    Phosphatidylinostitol-3-kinase (PI3K) is the potential anticancer target in the PI3K/Akt/ mTOR pathway. Here we reviewed the ATP-competitive small molecule PI3K inhibitors in the past few years, including the pan Class I PI3K inhibitors, the isoform-specific PI3K inhibitors and/or the PI3K/mTOR dual inhibitors. PMID:27769061

  9. Structure-based discovery of the first allosteric inhibitors of cyclin-dependent kinase 2.

    PubMed

    Rastelli, Giulio; Anighoro, Andrew; Chripkova, Martina; Carrassa, Laura; Broggini, Massimo

    2014-01-01

    Allosteric targeting of protein kinases via displacement of the structural αC helix with type III allosteric inhibitors is currently gaining a foothold in drug discovery. Recently, the first crystal structure of CDK2 with an open allosteric pocket adjacent to the αC helix has been described, prospecting new opportunities to design more selective inhibitors, but the structure has not yet been exploited for the structure-based design of type III allosteric inhibitors. In this work we report the results of a virtual screening campaign that resulted in the discovery of the first-in-class type III allosteric ligands of CDK2. Using a combination of docking and post-docking analyses made with our tool BEAR, 7 allosteric ligands (hit rate of 20%) with micromolar affinity for CDK2 were identified, some of them inhibiting the growth of breast cancer cell lines in the micromolar range. Competition experiments performed in the presence of the ATP-competitive inhibitor staurosporine confirmed that the 7 ligands are truly allosteric, in agreement with their design. Of these, compound 2 bound CDK2 with an EC50 value of 3 μM and inhibited the proliferation of MDA-MB231 and ZR-75-1 breast cancer cells with IC50 values of approximately 20 μM, while compound 4 had an EC50 value of 71 μM and IC50 values around 4 μM. Remarkably, the most potent compound 4 was able to selectively inhibit CDK2-mediated Retinoblastoma phosphorylation, confirming that its mechanism of action is fully compatible with a selective inhibition of CDK2 phosphorylation in cells. Finally, hit expansion through analog search of the most potent inhibitor 4 revealed an additional ligand 4g with similar in vitro potency on breast cancer cells.

  10. Cross-interactions of two p38 mitogen-activated protein (MAP) kinase inhibitors and two cholecystokinin (CCK) receptor antagonists with the CCK1 receptor and p38 MAP kinase.

    PubMed

    Morel, Caroline; Ibarz, Géraldine; Oiry, Catherine; Carnazzi, Eric; Bergé, Gilbert; Gagne, Didier; Galleyrand, Jean-Claude; Martinez, Jean

    2005-06-03

    Although SB202190 and SB203580 are described as specific p38 MAP kinase inhibitors, several reports have indicated that other enzymes are also sensitive to SB203580. Using a pharmacological approach, we report for the first time that compounds SB202190 and SB203580 were able to directly and selectively interact with a G-protein-coupled receptor, namely the cholecystokinin receptor subtype CCK1, but not with the CCK2 receptor. We demonstrated that these compounds were non-competitive antagonists of the CCK1 receptor at concentrations typically used to inhibit protein kinases. By chimeric construction of the CCK2 receptor, we determined the involvement of two CCK1 receptor intracellular loops in the binding of SB202190 and SB203580. We also showed that two CCK antagonists, L364,718 and L365,260, were able to regulate p38 mitogen-activated protein (MAP) kinase activity. Using a reporter gene strategy and immunoblotting experiments, we demonstrated that both CCK antagonists inhibited selectively the enzymatic activity of p38 MAP kinase. Kinase assays suggested that this inhibition resulted from a direct interaction with both CCK antagonists. Molecular modeling simulations suggested that this interaction occurs in the ATP binding pocket of p38 MAP kinase. These results suggest that SB202190 and SB203580 bind to the CCK1 receptor and, as such, these compounds should be used with caution in models that express this receptor. We also found that L364,718 and L365,260, two CCK receptor antagonists, directly interacted with p38 MAP kinase and inhibited its activity. These findings suggest that the CCK1 receptor shares structural analogies with the p38 MAP kinase ATP binding site. They open the way to potential design of either a new family of MAP kinase inhibitors from CCK1 receptor ligand structures or new CCK1 receptor ligands based on p38 MAP kinase inhibitor structures.

  11. Discovery of orally active pyrrolopyridine- and aminopyridine-based Met kinase inhibitors

    SciTech Connect

    Cai, Zhen-Wei; Wei, Donna; Schroeder, Gretchen M.; Cornelius, Lyndon A.M.; Kim, Kyoung; Chen, Xiao-Tao; Schmidt, Robert J.; Williams, David K.; Tokarski, John S.; An, Yongmi; Sack, John S.; Manne, Veeraswamy; Kamath, Amrita; Zhang, Yueping; Marathe, Punit; Hunt, John T.; Lombardo, Louis J.; Fargnoli, Joseph; Borzilleri, Robert M.

    2008-09-10

    A series of acylurea analogs derived from pyrrolopyridine and aminopyridine scaffolds were identified as potent inhibitors of Met kinase activity. The SAR at various positions of the two kinase scaffolds was investigated. These studies led to the discovery of compounds 3b and 20b, which demonstrated favorable pharmacokinetic properties in mice and significant antitumor activity in a human gastric carcinoma xenograft model.

  12. MAP KINASE ERK 1/2 INHIBITORS INDUCE DYSMORPHOLOGY IN MOUSE WHOLE EMBRYO CULTURE

    EPA Science Inventory

    ROSEN, M.B. and E. S. HUNTER. Reproductive Toxicology Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina. MAP kinase Erk1/2 inhibitors induce dysmorphology in mouse whole embryo culture.

    MAP Kinase signal transduction is associated with a variety ...

  13. Cardiotoxicity Associated with the Tyrosine Kinase Inhibitor Sunitinib

    PubMed Central

    Chu, Tammy F.; Rupnick, Maria A.; Kerkela, Risto; Dallabrida, Susan M.; Zurakowski, David; Nguyen, Lisa; Woulfe, Kathleen; Pravda, Elke; Cassiola, Flavia; Desai, Jayesh; George, Suzanne; Morgan, Jeffrey A.; Harris, David; Ismail, Nesreen S.; Chen, Jey-Hsin; Schoen, Frederick J.

    2008-01-01

    Background Tyrosine kinase inhibitors (TKIs) have advanced cancer treatment. Sunitinib, a recently-approved, multi-targeted TKI, prolongs survival for patients with metastatic renal cell carcinoma (RCC) and gastrointestinal stromal tumor (GIST), but concerns about cardiac safety have arisen with this agent. Methods To determine the cardiovascular risk associated with sunitinib, we reviewed all cardiovascular events in patients with imatinib-resistant, metastatic GIST at the Dana-Farber Cancer Institute enrolled in a Phase I/II protocol evaluating the efficacy of the drug (n=75). Sunitinib’s effects on left ventricular ejection fraction (LVEF) and blood pressure (BP) were also examined. Studies in isolated cardiomyocytes and mice investigated potential mechanisms of sunitinib-associated cardiac effects. Findings Eleven percent (8/75) of subjects suffered a cardiovascular event with congestive heart failure (CHF) occurring in 8% (6/75) of the population. Twenty-eight percent (10/36) of patients treated at the FDA-approved dose had LVEF declines of ≥ 10 EF%, and nineteen percent (7/36) experienced LVEF declines of ≥ 15 EF%. Sunitinib induced significant increases in mean systolic and diastolic BP in patients, and 47% (35/75) of individuals developed hypertension (HTN) (>150/100 mmHg). CHF and LV dysfunction generally responded to withholding drug and instituting medical management. In mice and cultured cardiomyocytes, sunitinib caused mitochondrial injury and cardiomyocyte apoptosis. Interpretation Sunitinib treatment can lead to HTN, LVEF decline, and/or CHF. Experimental studies suggest that this is due, at least in part, to direct cardiomyocyte toxicity which may be exacerbated by HTN. Patients treated with sunitinib should receive close monitoring and prompt treatment for HTN and/or LVEF decline. PMID:18083403

  14. Drug-drug interactions with tyrosine-kinase inhibitors: a clinical perspective.

    PubMed

    van Leeuwen, Roelof W F; van Gelder, Teun; Mathijssen, Ron H J; Jansman, Frank G A

    2014-07-01

    In the past decade, many tyrosine-kinase inhibitors have been introduced in oncology and haemato-oncology. Because this new class of drugs is extensively used, serious drug-drug interactions are an increasing risk. In this Review, we give a comprehensive overview of known or suspected drug-drug interactions between tyrosine-kinase inhibitors and other drugs. We discuss all haemato-oncological and oncological tyrosine-kinase inhibitors that had been approved by Aug 1, 2013, by the US Food and Drug Administration or the European Medicines Agency. Various clinically relevant drug interactions with tyrosine-kinase inhibitors have been identified. Most interactions concern altered bioavailability due to altered stomach pH, metabolism by cytochrome P450 isoenzymes, and prolongation of the QTc interval. To guarantee the safe use of tyrosine-kinase inhibitors, a drugs review for each patient is needed. This Review provides specific recommendations to guide haemato-oncologists, oncologists, and clinical pharmacists, through the process of managing drug-drug interactions during treatment with tyrosine-kinase inhibitors in daily clinical practice.

  15. New applications for known drugs: Human glycogen synthase kinase 3 inhibitors as modulators of Aspergillus fumigatus growth.

    PubMed

    Sebastián, Víctor; Manoli, Maria-Tsampika; Pérez, Daniel I; Gil, Carmen; Mellado, Emilia; Martínez, Ana; Espeso, Eduardo A; Campillo, Nuria E

    2016-06-30

    Invasive aspergillosis (IA) is one of the most severe forms of fungi infection. IA disease is mainly due to Aspergillus fumigatus, an air-borne opportunistic pathogen. Mortality rate caused by IA is still very high (50-95%), because of difficulty in early diagnostics and reduced antifungal treatment options, thus new and efficient drugs are necessary. The aim of this work is, using Aspergillus nidulans as non-pathogen model, to develop efficient drugs to treat IA. The recent discovered role of glycogen synthase kinase-3 homologue, GskA, in A. fumigatus human infection and our previous experience on human GSK-3 inhibitors focus our attention on this kinase as a target for the development of antifungal drugs. With the aim to identify effective inhibitors of colonial growth of A. fumigatus we use A. nidulans as an accurate model for in vivo and in silico studies. Several well-known human GSK-3β inhibitors were tested for inhibition of A. nidulans colony growth. Computational tools as docking studies and binding site prediction was used to explain the different biological profile of the tested inhibitors. Three of the five tested hGSK3β inhibitors are able to reduce completely the colonial growth by covalent bind to the enzyme. Therefore these compounds may be useful in different applications to eradicate IA.

  16. Widespread potential for growth-factor-driven resistance to anticancer kinase inhibitors

    PubMed Central

    Wilson, Timothy R.; Fridlyand, Jane; Yan, Yibing; Penuel, Elicia; Burton, Luciana; Chan, Emily; Peng, Jing; Lin, Eva; Wang, Yulei; Sosman, Jeff; Ribas, Antoni; Li, Jiang; Moffat, John; Sutherlin, Daniel P.; Koeppen, Hartmut; Merchant, Mark; Neve, Richard; Settleman, Jeff

    2013-01-01

    Mutationally activated kinases define a clinically validated class of targets for cancer drug therapy1. However, the efficacy of kinase inhibitors in patients whose tumours harbour such alleles is invariably limited by innate or acquired drug resistance2,3. The identification of resistance mechanisms has revealed a recurrent theme—the engagement of survival signals redundant to those transduced by the targeted kinase4. Cancer cells typically express multiple receptor tyrosine kinases (RTKs) that mediate signals that converge on common critical downstream cell-survival effectors—most notably, phosphatidylinositol-3-OH kinase (PI(3)K) and mitogen-activated protein kinase (MAPK)5. Consequently, an increase in RTK-ligand levels, through autocrine tumour-cell production, paracrine contribution from tumour stroma6 or systemic production, could confer resistance to inhibitors of an oncogenic kinase with a similar signalling output. Here, using a panel of kinase-‘addicted’ human cancer cell lines, we found that most cells can be rescued from drug sensitivity by simply exposing them to one or more RTK ligands. Among the findings with clinical implications was the observation that hepatocyte growth factor (HGF) confers resistance to the BRAF inhibitor PLX4032 (vemurafenib) in BRAF-mutant melanoma cells. These observations highlight the extensive redundancy of RTK-transduced signalling in cancer cells and the potentially broad role of widely expressed RTK ligands in innate and acquired resistance to drugs targeting oncogenic kinases. PMID:22763448

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

    PubMed

    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.

  18. Virtual screening of selective multitarget kinase inhibitors by combinatorial support vector machines.

    PubMed

    Ma, X H; Wang, R; Tan, C Y; Jiang, Y Y; Lu, T; Rao, H B; Li, X Y; Go, M L; Low, B C; Chen, Y Z

    2010-10-04

    Multitarget agents have been increasingly explored for enhancing efficacy and reducing countertarget activities and toxicities. Efficient virtual screening (VS) tools for searching selective multitarget agents are desired. Combinatorial support vector machines (C-SVM) were tested as VS tools for searching dual-inhibitors of 11 combinations of 9 anticancer kinase targets (EGFR, VEGFR, PDGFR, Src, FGFR, Lck, CDK1, CDK2, GSK3). C-SVM trained on 233-1,316 non-dual-inhibitors correctly identified 26.8%-57.3% (majority >36%) of the 56-230 intra-kinase-group dual-inhibitors (equivalent to the 50-70% yields of two independent individual target VS tools), and 12.2% of the 41 inter-kinase-group dual-inhibitors. C-SVM were fairly selective in misidentifying as dual-inhibitors 3.7%-48.1% (majority <20%) of the 233-1,316 non-dual-inhibitors of the same kinase pairs and 0.98%-4.77% of the 3,971-5,180 inhibitors of other kinases. C-SVM produced low false-hit rates in misidentifying as dual-inhibitors 1,746-4,817 (0.013%-0.036%) of the 13.56 M PubChem compounds, 12-175 (0.007%-0.104%) of the 168 K MDDR compounds, and 0-84 (0.0%-2.9%) of the 19,495-38,483 MDDR compounds similar to the known dual-inhibitors. C-SVM was compared to other VS methods Surflex-Dock, DOCK Blaster, kNN and PNN against the same sets of kinase inhibitors and the full set or subset of the 1.02 M Zinc clean-leads data set. C-SVM produced comparable dual-inhibitor yields, slightly better false-hit rates for kinase inhibitors, and significantly lower false-hit rates for the Zinc clean-leads data set. Combinatorial SVM showed promising potential for searching selective multitarget agents against intra-kinase-group kinases without explicit knowledge of multitarget agents.

  19. Kinase Inhibitor Screening Identifies Cyclin-Dependent Kinases and Glycogen Synthase Kinase 3 as Potential Modulators of TDP-43 Cytosolic Accumulation during Cell Stress.

    PubMed

    Moujalled, Diane; James, Janine L; Parker, Sarah J; Lidgerwood, Grace E; Duncan, Clare; Meyerowitz, Jodi; Nonaka, Takashi; Hasegawa, Masato; Kanninen, Katja M; Grubman, Alexandra; Liddell, Jeffrey R; Crouch, Peter J; White, Anthony R

    2013-01-01

    Abnormal processing of TAR DNA binding protein 43 (TDP-43) has been identified as a major factor in neuronal degeneration during amyotrophic lateral sclerosis (ALS) or frontotemporal lobar degeneration (FTLD). It is unclear how changes to TDP-43, including nuclear to cytosolic translocation and subsequent accumulation, are controlled in these diseases. TDP-43 is a member of the heterogeneous ribonucleoprotein (hnRNP) RNA binding protein family and is known to associate with cytosolic RNA stress granule proteins in ALS and FTLD. hnRNP trafficking and accumulation is controlled by the action of specific kinases including members of the mitogen-activated protein kinase (MAPK) pathway. However, little is known about how kinase pathways control TDP-43 movement and accumulation. In this study, we used an in vitro model of TDP-43-positve stress granule formation to screen for the effect of kinase inhibitors on TDP-43 accumulation. We found that while a number of kinase inhibitors, particularly of the MAPK pathways modulated both TDP-43 and the global stress granule marker, human antigen R (HuR), multiple inhibitors were more specific to TDP-43 accumulation, including inhibitors of cyclin-dependent kinases (CDKs) and glycogen synthase kinase 3 (GSK3). Close correlation was observed between effects of these inhibitors on TDP-43, hnRNP K and TIAR, but often with different effects on HuR accumulation. This may indicate a potential interaction between TDP-43, hnRNP K and TIAR. CDK inhibitors were also found to reverse pre-formed TDP-43-positive stress granules and both CDK and GSK3 inhibitors abrogated the accumulation of C-terminal TDP-43 (219-414) in transfected cells. Further studies are required to confirm the specific kinases involved and whether their action is through phosphorylation of the TDP-43 binding partner hnRNP K. This knowledge provides a valuable insight into the mechanisms controlling abnormal cytoplasmic TDP-43 accumulation and may herald new opportunities

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

    PubMed

    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.

  1. Crystal Structure of the Ca2+/Calmodulin-dependent Protein Kinase Kinase in Complex with the Inhibitor STO-609*

    PubMed Central

    Kukimoto-Niino, Mutsuko; Yoshikawa, Seiko; Takagi, Tetsuo; Ohsawa, Noboru; Tomabechi, Yuri; Terada, Takaho; Shirouzu, Mikako; Suzuki, Atsushi; Lee, Suni; Yamauchi, Toshimasa; Okada-Iwabu, Miki; Iwabu, Masato; Kadowaki, Takashi; Minokoshi, Yasuhiko; Yokoyama, Shigeyuki

    2011-01-01

    Ca2+/calmodulin (CaM)-dependent protein kinase (CaMK) kinase (CaMKK) is a member of the CaMK cascade that mediates the response to intracellular Ca2+ elevation. CaMKK phosphorylates and activates CaMKI and CaMKIV, which directly activate transcription factors. In this study, we determined the 2.4 Å crystal structure of the catalytic kinase domain of the human CaMKKβ isoform complexed with its selective inhibitor, STO-609. The structure revealed that CaMKKβ lacks the αD helix and that the equivalent region displays a hydrophobic molecular surface, which may reflect its unique substrate recognition and autoinhibition. Although CaMKKβ lacks the activation loop phosphorylation site, the activation loop is folded in an active-state conformation, which is stabilized by a number of interactions between amino acid residues conserved among the CaMKK isoforms. An in vitro analysis of the kinase activity confirmed the intrinsic activity of the CaMKKβ kinase domain. Structure and sequence analyses of the STO-609-binding site revealed amino acid replacements that may affect the inhibitor binding. Indeed, mutagenesis demonstrated that the CaMKKβ residue Pro274, which replaces the conserved acidic residue of other protein kinases, is an important determinant for the selective inhibition by STO-609. Therefore, the present structure provides a molecular basis for clarifying the known biochemical properties of CaMKKβ and for designing novel inhibitors targeting CaMKKβ and the related protein kinases. PMID:21504895

  2. The third-time chronic myeloid leukemia in lymphoblastic crisis with ABL1 kinase mutation induced by decitabine, dexamethason combined with nilotinib and dasatinib

    PubMed Central

    Wang, Suli; Qiao, Chun; Zhu, Yu; Shen, Wenyi; Li, Jianyong

    2016-01-01

    Abstract Blast crisis (BC) is the major remaining challenge in the management of chronic myeloid leukemia (CML). The prognosis of the BC patient who carries ABL kinase mutation is very poor. One patient, with lymphoid CML-BC third time, was detected with T315A/F359I/M244V compound mutation by direct sequencing after treatment with tyrosine kinase inhibitions three years. The patient was treated with decitabine, dexamethasone, in combination with nilotinib and dasatinib. Then this patient received a complete hematologic response and cytogenetic response after two cycles of treatment. PMID:28191543

  3. Design, synthesis, and biological activity of urea derivatives as anaplastic lymphoma kinase inhibitors.

    PubMed

    af Gennäs, Gustav Boije; Mologni, Luca; Ahmed, Shaheen; Rajaratnam, Mohanathas; Marin, Oriano; Lindholm, Niko; Viltadi, Michela; Gambacorti-Passerini, Carlo; Scapozza, Leonardo; Yli-Kauhaluoma, Jari

    2011-09-05

    In anaplastic large-cell lymphomas, chromosomal translocations involving the kinase domain of anaplastic lymphoma kinase (ALK), generally fused to the 5' part of the nucleophosmin gene, produce highly oncogenic ALK fusion proteins that deregulate cell cycle, apoptosis, and differentiation in these cells. Other fusion oncoproteins involving ALK, such as echinoderm microtubule-associated protein-like 4-ALK, were recently found in patients with non-small-cell lung, breast, and colorectal cancers. Recent research has focused on the development of inhibitors for targeted therapy of these ALK-positive tumors. Because kinase inhibitors that target the inactive conformation are thought to be more specific than ATP-targeted inhibitors, we investigated the possibility of using two known inhibitors, doramapimod and sorafenib, which target inactive kinases, to design new urea derivatives as ALK inhibitors. We generated a homology model of ALK in its inactive conformation complexed with doramapimod or sorafenib in its active site. The results elucidated why doramapimod is a weak inhibitor and why sorafenib does not inhibit ALK. Virtual screening of commercially available compounds using the homology model of ALK yielded candidate inhibitors, which were tested using biochemical assays. Herein we present the design, synthesis, biological activity, and structure-activity relationships of a novel series of urea compounds as potent ALK inhibitors. Some compounds showed inhibition of purified ALK in the high nanomolar range and selective antiproliferative activity on ALK-positive cells.

  4. Fragment-Based Discovery of a Dual pan-RET/VEGFR2 Kinase Inhibitor Optimized for Single-Agent Polypharmacology.

    PubMed

    Frett, Brendan; Carlomagno, Francesca; Moccia, Maria Luisa; Brescia, Annalisa; Federico, Giorgia; De Falco, Valentina; Admire, Brittany; Chen, Zhongzhu; Qi, Wenqing; Santoro, Massimo; Li, Hong-yu

    2015-07-20

    Oncogenic conversion of the RET (rearranged during transfection) tyrosine kinase is associated with several cancers. A fragment-based chemical screen led to the identification of a novel RET inhibitor, Pz-1. Modeling and kinetic analysis identified Pz-1 as a type II tyrosine kinase inhibitor that is able to bind the "DFG-out" conformation of the kinase. Importantly, from a single-agent polypharmacology standpoint, Pz-1 was shown to be active on VEGFR2, which can block the blood supply required for RET-stimulated growth. In cell-based assays, 1.0 nM of Pz-1 strongly inhibited phosphorylation of all tested RET oncoproteins. At 1.0 mg kg(-1)  day(-1) per os, Pz-1 abrogated the formation of tumors induced by RET-mutant fibroblasts and blocked the phosphorylation of both RET and VEGFR2 in tumor tissue. Pz-1 featured no detectable toxicity at concentrations of up to 100.0 mg kg(-1), which indicates a large therapeutic window. This study validates the effectiveness and usefulness of a medicinal chemistry/polypharmacology approach to obtain an inhibitor capable of targeting multiple oncogenic pathways.

  5. Purine inhibitors of protein kinases, G proteins and polymerases

    DOEpatents

    Gray, Nathanael S.; Schultz, Peter; Kim, Sung-Hou; Meijer, Laurent

    2001-07-03

    The present invention relates to purine analogs that inhibit, inter alia, protein kinases, G-proteins and polymerases. In addition, the present invention relates to methods of using such purine analogs to inhibit protein kinases, G-proteins, polymerases and other cellular processes and to treat cellular proliferative diseases.

  6. Investigation of potential glycogen synthase kinase 3 inhibitors using pharmacophore mapping and virtual screening.

    PubMed

    Dessalew, Nigus; Bharatam, Prasad V

    2006-09-01

    Glycogen synthase kinase-3 is a serine/threonine kinase that has attracted significant drug discovery attention in recent years. To investigate the identification of new potential glycogen synthase kinase-3 inhibitors, a pharmacophore mapping study was carried out using a set of 21 structurally diverse glycogen synthase kinase-3 inhibitors. A hypothesis containing four features: two hydrophobic, one hydrogen bond donor and another hydrogen bond acceptor was found to be the best from the 10 common feature hypotheses produced by HipHop module of Catalyst. The best hypothesis has a high cost of 156.592 and higher best fit values were obtained for the 21 inhibitors using this best hypothesis than the other HipHop hypotheses. The best hypothesis was then used to screen electronically the NCI2000 database. The hits obtained were docked into glycogen synthase kinase-3beta active site. A total of five novel potential leads were proposed after: (i) visual examination of how well they dock into the glycogen synthase kinase-3beta-binding site, (ii) comparative analysis of their FlexX, G-Score, PMF-Score, ChemScore and D-Scores values, (iii) comparison of their best fit value with the known inhibitors and (iv) examination of the how the hits retain interactions with the important amino acid residues of glycogen synthase kinase-3beta-binding site.

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

    PubMed

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

    2017-02-28

    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.

  8. p62(dok), a negative regulator of Ras and mitogen-activated protein kinase (MAPK) activity, opposes leukemogenesis by p210(bcr-abl).

    PubMed

    Di Cristofano, A; Niki, M; Zhao, M; Karnell, F G; Clarkson, B; Pear, W S; Van Aelst, L; Pandolfi, P P

    2001-08-06

    p62(dok) has been identified as a substrate of many oncogenic tyrosine kinases such as the chronic myelogenous leukemia (CML) chimeric p210(bcr-abl) oncoprotein. It is also phosphorylated upon activation of many receptors and cytoplamic tyrosine kinases. However, the biological functions of p62(dok) in normal cell signaling as well as in p210(bcr-abl) leukemogenesis are as yet not fully understood. Here we show, in hemopoietic and nonhemopoietic cells derived from p62(dok)-(/)- mice, that the loss of p62(dok) results in increased cell proliferation upon growth factor treatment. Moreover, Ras and mitogen-activated protein kinase (MAPK) activation is markedly sustained in p62(dok)-(/)- cells after the removal of growth factor. However, p62(dok) inactivation does not affect DNA damage and growth factor deprivation-induced apoptosis. Furthermore, p62(dok) inactivation causes a significant shortening in the latency of the fatal myeloproliferative disease induced by retroviral-mediated transduction of p210(bcr-abl) in bone marrow cells. These data indicate that p62(dok) acts as a negative regulator of growth factor-induced cell proliferation, at least in part through downregulating Ras/MAPK signaling pathway, and that p62(dok) can oppose leukemogenesis by p210(bcr-abl).

  9. Methods for Investigation of Targeted Kinase Inhibitor Therapy using Chemical Proteomics and Phosphorylation Profiling

    PubMed Central

    Fang, Bin; Haura, Eric B.; Smalley, Keiran S.; Eschrich, Steven A.; Koomen, John M.

    2010-01-01

    Phosphorylation acts as a molecular switch for many regulatory events in signaling pathways that drive cell division, proliferation, and apoptosis. Because of the critical nature of these protein post-translational modifications in cancer, drug development programs often focus on inhibitors for kinases and phosphatases, which control protein phosphorylation. Numerous kinase inhibitors have entered clinical use, but prediction of their efficacy and a molecular basis for patient response remain uncertain. Chemical proteomics, the combination of drug affinity chromatography with mass spectrometry, identifies potential target proteins that bind to the drugs. Phosphorylation profiling can complement chemical proteomics by cataloging modifications in the target kinases and their downstream substrates using phosphopeptide enrichment and quantitative mass spectrometry. These experiments shed light on the mechanism of disease development and illuminate candidate biomarkers to guide personalized therapeutic strategies. In this review, commonly applied technologies and workflows are discussed to illustrate the role of proteomics in examining tumor biology and therapeutic intervention using kinase inhibitors. PMID:20361944

  10. Identification of potent Yes1 kinase inhibitors using a library screening approach.

    PubMed

    Patel, Paresma R; Sun, Hongmao; Li, Samuel Q; Shen, Min; Khan, Javed; Thomas, Craig J; Davis, Mindy I

    2013-08-01

    Yes1 kinase has been implicated as a potential therapeutic target in a number of cancers including melanomas, breast cancers, and rhabdomyosarcomas. Described here is the development of a robust and miniaturized biochemical assay for Yes1 kinase that was applied in a high throughput screen (HTS) of kinase-focused small molecule libraries. The HTS provided 144 (17% hit rate) small molecule compounds with IC₅₀ values in the sub-micromolar range. Three of the most potent Yes1 inhibitors were then examined in a cell-based assay for inhibition of cell survival in rhabdomyosarcoma cell lines. Homology models of Yes1 were generated in active and inactive conformations, and docking of inhibitors supports binding to the active conformation (DFG-in) of Yes1. This is the first report of a large high throughput enzymatic activity screen for identification of Yes1 kinase inhibitors, thereby elucidating the polypharmacology of a variety of small molecules and clinical candidates.

  11. A Drosophila homolog of cyclase-associated proteins collaborates with the Abl tyrosine kinase to control midline axon pathfinding.

    PubMed

    Wills, Zachary; Emerson, Mark; Rusch, Jannette; Bikoff, Jay; Baum, Buzz; Perrimon, Norbert; Van Vactor, David

    2002-11-14

    We demonstrate that Drosophila capulet (capt), a homolog of the adenylyl cyclase-associated protein that binds and regulates actin in yeast, associates with Abl in Drosophila cells, suggesting a functional relationship in vivo. We find a robust and specific genetic interaction between capt and Abl at the midline choice point where the growth cone repellent Slit functions to restrict axon crossing. Genetic interactions between capt and slit support a model where Capt and Abl collaborate as part of the repellent response. Further support for this model is provided by genetic interactions that both capt and Abl display with multiple members of the Roundabout receptor family. These studies identify Capulet as part of an emerging pathway linking guidance signals to regulation of cytoskeletal dynamics and suggest that the Abl pathway mediates signals downstream of multiple Roundabout receptors.

  12. Computational Insights for the Discovery of Non-ATP Competitive Inhibitors of MAP Kinases

    PubMed Central

    Schnieders, Michael J.; Kaoud, Tamer S.; Yan, Chunli; Dalby, Kevin N.; Ren, Pengyu

    2014-01-01

    Due to their role in cellular signaling mitogen activated protein (MAP) kinases represent targets of pharmaceutical interest. However, the majority of known MAP kinase inhibitors compete with cellular ATP and target an ATP binding pocket that is highly conserved in the 500 plus representatives of the human protein kinase family. Here we review progress toward the development of non-ATP competitive MAP kinase inhibitors for the extracellular signal regulated kinases (ERK1/2), the c-jun N-terminal kinases (JNK1/2/3) and the p38 MAPKs (α, β, γ, and δ). Special emphasis is placed on the role of computational methods in the drug discovery process for MAP kinases. Topics include recent advances in X-ray crystallography theory that improve the MAP kinase structures essential to structure-based drug discovery, the use of molecular dynamics to understand the conformational heterogeneity of the activation loop and inhibitors discovered by virtual screening. The impact of an advanced polarizable force field such as AMOEBA used in conjunction with sophisticated kinetic and thermodynamic simulation methods is also discussed. PMID:22316156

  13. Identification of novel polo-like kinase 1 inhibitors by a hybrid virtual screening.

    PubMed

    Lu, Shuai; Sun, Shan-Liang; Liu, Hai-Chun; Chen, Ya-Dong; Yuan, Hao-Liang; Gao, Yi-Ping; Yang, Pei; Lu, Tao

    2012-08-01

    Polo-like kinase 1 is an important and attractive oncological target that plays a key role in mitosis and cytokinesis. A combined pharmacophore- and docking-based virtual screening was performed to identify novel polo-like kinase 1 inhibitors. A total of 34 hit compounds were selected and tested in vitro, and some compounds showed inhibition of polo-like kinase 1 and human tumor cell growth. The most potent compound (66) inhibited polo-like kinase 1 with an IC(50) value of 6.99 μm. The docked binding models of two hit compounds were discussed in detail. These compounds contained novel chemical scaffolds and may be used as foundations for the development of novel classes of polo-like kinase 1 inhibitors.

  14. The noni anthraquinone damnacanthal is a multi-kinase inhibitor with potent anti-angiogenic effects.

    PubMed

    García-Vilas, Javier A; Pino-Ángeles, Almudena; Martínez-Poveda, Beatriz; Quesada, Ana R; Medina, Miguel Ángel

    2017-01-28

    The natural bioactive compound damnacanthal inhibits several tyrosine kinases. Herein, we show that -in fact- damancanthal is a multi kinase inhibitor. A docking and molecular dynamics simulation approach allows getting further insight on the inhibitory effect of damnacanthal on three different kinases: vascular endothelial growth factor receptor-2, c-Met and focal adhesion kinase. Several of the kinases targeted and inhibited by damnacanthal are involved in angiogenesis. Ex vivo and in vivo experiments clearly demonstrate that, indeed, damnacanthal is a very potent inhibitor of angiogenesis. A number of in vitro assays contribute to determine the specific effects of damnacanthal on each of the steps of the angiogenic process, including inhibition of tubulogenesis, endothelial cell proliferation, survival, migration and production of extracellular matrix remodeling enzyme. Taken altogether, these results suggest that damancanthal could have potential interest for the treatment of cancer and other angiogenesis-dependent diseases.

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

    PubMed Central

    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. PMID:25523586

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

    PubMed

    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.

  17. Novel plant-specific cyclin-dependent kinase inhibitors induced by biotic and abiotic stresses.

    PubMed

    Peres, Adrian; Churchman, Michelle L; Hariharan, Srivaidehirani; Himanen, Kristiina; Verkest, Aurine; Vandepoele, Klaas; Magyar, Zoltan; Hatzfeld, Yves; Van Der Schueren, Els; Beemster, Gerrit T S; Frankard, Valerie; Larkin, John C; Inzé, Dirk; De Veylder, Lieven

    2007-08-31

    The EL2 gene of rice (Oryza sativa), previously classified as early response gene against the potent biotic elicitor N-acetylchitoheptaose and encoding a short polypeptide with unknown function, was identified as a novel cell cycle regulatory gene related to the recently reported SIAMESE (SIM) gene of Arabidopsis thaliana. Iterative two-hybrid screens, in vitro pull-down assays, and fluorescence resonance energy transfer analyses showed that Orysa; EL2 binds the cyclin-dependent kinase (CDK) CDKA1;1 and D-type cyclins. No interaction was observed with the plant-specific B-type CDKs. The amino acid motif ELERFL was identified to be essential for cyclin, but not for CDK binding. Orysa;EL2 impaired the ability of Orysa; CYCD5;3 to complement a budding yeast (Saccharomyces cerevisiae) triple CLN mutant, whereas recombinant protein inhibited CDK activity in vitro. Moreover, Orysa;EL2 was able to rescue the multicellular trichome phenotype of sim mutants of Arabidopsis, unequivocally demonstrating that Orysa;EL2 operates as a cell cycle inhibitor. Orysa;EL2 mRNA levels were induced by cold, drought, and propionic acid. Our data suggest that Orysa;EL2 encodes a new type of plant CDK inhibitor that links cell cycle progression with biotic and abiotic stress responses.

  18. Structure-based design of isoquinoline-5-sulfonamide inhibitors of protein kinase B.

    PubMed

    Collins, Ian; Caldwell, John; Fonseca, Tatiana; Donald, Alastair; Bavetsias, Vassilios; Hunter, Lisa-Jane K; Garrett, Michelle D; Rowlands, Martin G; Aherne, G Wynne; Davies, Thomas G; Berdini, Valerio; Woodhead, Steven J; Davis, Deborah; Seavers, Lisa C A; Wyatt, Paul G; Workman, Paul; McDonald, Edward

    2006-02-15

    Structure-based drug design of novel isoquinoline-5-sulfonamide inhibitors of PKB as potential antitumour agents was investigated. Constrained pyrrolidine analogues that mimicked the bound conformation of linear prototypes were identified and investigated by co-crystal structure determinations with the related protein PKA. Detailed variation in the binding modes between inhibitors with similar overall conformations was observed. Potent PKB inhibitors from this series inhibited GSK3beta phosphorylation in cellular assays, consistent with inhibition of PKB kinase activity in cells.

  19. The lack of target specificity of small molecule anticancer kinase inhibitors is correlated with their ability to damage myocytes in vitro

    SciTech Connect

    Hasinoff, Brian B. Patel, Daywin

    2010-12-01

    Many new targeted small molecule anticancer kinase inhibitors are actively being developed. However, the clinical use of some kinase inhibitors has been shown to result in cardiotoxicity. In most cases the mechanisms by which they exert their cardiotoxicity are not well understood. We have used large scale profiling data on 8 FDA-approved tyrosine kinase inhibitors and 10 other kinase inhibitors to a panel of 317 kinases in order to correlate binding constants and kinase inhibitor binding selectivity scores with kinase inhibitor-induced damage to neonatal rat cardiac myocytes. The 18 kinase inhibitors that were the subject of this study were: canertinib, dasatinib, dovitinib, erlotinib, flavopiridol, gefitinib, imatinib, lapatinib, midostaurin, motesanib, pazopanib, sorafenib, staurosporine, sunitinib, tandutinib, tozasertib, vandetanib and vatalanib. The combined tyrosine kinase and serine-threonine kinase selectivity scores were highly correlated with the myocyte-damaging effects of the kinase inhibitors. This result suggests that myocyte damage was due to a lack of target selectivity to binding of both tyrosine kinases and serine-threonine kinases, and was not due to binding to either group specifically. Finally, the strength of kinase inhibitor binding for 290 kinases was examined for correlations with myocyte damage. Kinase inhibitor binding was significantly correlated with myocyte damage for 12 kinases. Thus, myocyte damage may be multifactorial in nature with the inhibition of a number of kinases involved in producing kinase inhibitor-induced myocyte damage.

  20. Crystal structure of a human cyclin-dependent kinase 6 complexwith a flavonol inhibitor, Fisetin

    SciTech Connect

    Lu, Heshu; Chang, Debbie J.; Baratte, Blandine; Meijer, Laurent; Schulze-Gahmen, Ursula

    2005-01-10

    Cyclin-dependent kinases (CDKs) play a central role in cell cycle control, apoptosis, transcription and neuronal functions. They are important targets for the design of drugs with anti-mitotic and/or anti-neurodegenerative effects. CDK4 and CDK6 form a subfamily among the CDKs in mammalian cells, as defined by sequence similarities. Compared to CDK2 and CDK5, structural information on CDK4 and CDK6 is sparse. We describe here the crystal structure of human CDK6 in complex with a viral cyclin and a flavonol inhibitor, fisetin. Fisetin binds to the active form of CDK6, forming hydrogen bonds with the side chains of residues in the binding pocket that undergo large conformational changes during CDK activation by cyclin binding. The 4-keto group and the 3-hydroxyl group of fisetin are hydrogen bonded with the backbone in the hinge region between the N-terminal and C-terminal kinase domain, as has been observed for many CDK inhibitors. However, CDK2 and HCK kinase in complex with other flavone inhibitors such as quercetin and flavopiridol showed a different binding mode with the inhibitor rotated by about 180. The structural information of the CDK6-fisetin complex is correlated with the binding affinities of different flavone inhibitors for CDK6. This complex structure is the first description of an inhibitor complex with a kinase from the CDK4/6 subfamily and can provide a basis for selecting and designing inhibitor compounds with higher affinity and specificity.

  1. Reduced Proteolytic Shedding of Receptor Tyrosine Kinases is a Post-Translational Mechanism of Kinase Inhibitor Resistance

    PubMed Central

    Miller, Miles A.; Oudin, Madeleine J.; Sullivan, Ryan J.; Wang, Stephanie J.; Meyer, Aaron S.; Im, Hyungsoon; Frederick, Dennie T.; Tadros, Jenny; Griffith, Linda G.; Lee, Hakho; Weissleder, Ralph; Flaherty, Keith T.; Gertler, Frank B.; Lauffenburger, Douglas A.

    2016-01-01

    Kinase inhibitor resistance often involves upregulation of poorly understood “bypass” signaling pathways. Here, we show that extracellular proteomic adaptation is one path to bypass signaling and drug resistance. Proteolytic shedding of surface receptors, which can provide negative feedback on signaling activity, is blocked by kinase inhibitor treatment and enhances bypass signaling. In particular, MEK inhibition broadly decreases shedding of multiple receptor tyrosine kinases (RTKs) including HER4, MET, and most prominently AXL, an ADAM10 and ADAM17 substrate, thus increasing surface RTK levels and mitogenic signaling. Progression-free survival of melanoma patients treated with clinical BRAF/MEK inhibitors inversely correlates with RTK shedding reduction following treatment, as measured non-invasively in blood plasma. Disrupting protease inhibition by neutralizing TIMP1 improves MAPK inhibitor efficacy, and combined MAPK/AXL inhibition synergistically reduces tumor growth and metastasis in xenograft models. Altogether, extracellular proteomic rewiring through reduced RTK shedding represents a surprising mechanism for bypass signaling in cancer drug resistance. PMID:26984351

  2. Temporal quantitation of mutant Kit tyrosine kinase signaling attenuated by a novel thiophene kinase inhibitor OSI-930.

    PubMed

    Petti, Filippo; Thelemann, April; Kahler, Jen; McCormack, Siobhan; Castaldo, Linda; Hunt, Tony; Nuwaysir, Lydia; Zeiske, Lynn; Haack, Herbert; Sullivan, Laura; Garton, Andrew; Haley, John D

    2005-08-01

    OSI-930, a potent thiophene inhibitor of the Kit, KDR, and platelet-derived growth factor receptor tyrosine kinases, was used to selectively inhibit tyrosine phosphorylation downstream of juxtamembrane mutant Kit in the mast cell leukemia line HMC-1. Inhibition of Kit kinase activity resulted in a rapid dephosphorylation of Kit and inhibition of the downstream signaling pathways. Attenuation of Ras-Raf-Erk (phospho-Erk, phospho-p38), phosphatidyl inositol-3' kinase (phospho-p85, phospho-Akt, phospho-S6), and signal transducers and activators of transcription signaling pathways (phospho-STAT3/5/6) were measured by affinity liquid chromatography tandem mass spectrometry, by immunoblot, and by tissue microarrays of fixed cell pellets. To more globally define additional components of Kit signaling temporally altered by kinase inhibition, a novel multiplex quantitative isobaric peptide labeling approach was used. This approach allowed clustering of proteins by temporal expression patterns. Kit kinase, which dephosphorylates rapidly upon kinase inhibition, was shown to regulate both Shp-1 and BDP-1 tyrosine phosphatases and the phosphatase-interacting protein PSTPIP2. Interactions with SH2 domain adapters [growth factor receptor binding protein 2 (Grb2), Cbl, Slp-76] and SH3 domain adapters (HS1, cortactin, CD2BP3) were attenuated by inhibition of Kit kinase activity. Functional crosstalk between Kit and the non-receptor tyrosine kinases Fes/Fps, Fer, Btk, and Syk was observed. Inhibition of Kit modulated phosphorylation-dependent interactions with pathways controlling focal adhesion (paxillin, leupaxin, p130CAS, FAK1, the Src family kinase Lyn, Wasp, Fhl-3, G25K, Ack-1, Nap1, SH3P12/ponsin) and septin-actin complexes (NEDD5, cdc11, actin). The combined use of isobaric protein quantitation and expression clustering, immunoblot, and tissue microarray strategies allowed temporal measurement signaling pathways modulated by mutant Kit inhibition in a model of mast cell

  3. Purine inhibitors of protein kinases, G proteins and polymerases

    DOEpatents

    Gray, Nathanael S.; Schultz, Peter; Kim, Sung-Hou; Meijer, Laurent

    2004-10-12

    The present invention relates to 2-N-substituted 6-(4-methoxybenzylamino)-9-isopropylpurines that inhibit, inter alia, protein kinases, G-proteins and polymerases. In addition, the present invention relates to methods of using such 2-N-substituted 6-(4-methoxybenzylamino)-9-isopropylpurines to inhibit protein kinases, G-proteins, polymerases and other cellular processes and to treat cellular proliferative diseases.

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

    SciTech Connect

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

    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.

  5. Targeting Cyclin-Dependent Kinases in Human Cancers: From Small Molecules to Peptide Inhibitors

    PubMed Central

    Peyressatre, Marion; Prével, Camille; Pellerano, Morgan; Morris, May C.

    2015-01-01

    Cyclin-dependent kinases (CDK/Cyclins) form a family of heterodimeric kinases that play central roles in regulation of cell cycle progression, transcription and other major biological processes including neuronal differentiation and metabolism. Constitutive or deregulated hyperactivity of these kinases due to amplification, overexpression or mutation of cyclins or CDK, contributes to proliferation of cancer cells, and aberrant activity of these kinases has been reported in a wide variety of human cancers. These kinases therefore constitute biomarkers of proliferation and attractive pharmacological targets for development of anticancer therapeutics. The structural features of several of these kinases have been elucidated and their molecular mechanisms of regulation characterized in depth, providing clues for development of drugs and inhibitors to disrupt their function. However, like most other kinases, they constitute a challenging class of therapeutic targets due to their highly conserved structural features and ATP-binding pocket. Notwithstanding, several classes of inhibitors have been discovered from natural sources, and small molecule derivatives have been synthesized through rational, structure-guided approaches or identified in high throughput screens. The larger part of these inhibitors target ATP pockets, but a growing number of peptides targeting protein/protein interfaces are being proposed, and a small number of compounds targeting allosteric sites have been reported. PMID:25625291

  6. Abelson Kinase Inhibitors Are Potent Inhibitors of Severe Acute Respiratory Syndrome Coronavirus and Middle East Respiratory Syndrome Coronavirus Fusion

    PubMed Central

    Coleman, Christopher M.; Sisk, Jeanne M.; Mingo, Rebecca M.; Nelson, Elizabeth A.; White, Judith M.

    2016-01-01

    ABSTRACT The highly pathogenic severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) cause significant morbidity and morality. There is currently no approved therapeutic for highly pathogenic coronaviruses, even as MERS-CoV is spreading throughout the Middle East. We previously screened a library of FDA-approved drugs for inhibitors of coronavirus replication in which we identified Abelson (Abl) kinase inhibitors, including the anticancer drug imatinib, as inhibitors of both SARS-CoV and MERS-CoV in vitro. Here we show that the anti-CoV activity of imatinib occurs at the early stages of infection, after internalization and endosomal trafficking, by inhibiting fusion of the virions at the endosomal membrane. We specifically identified the imatinib target, Abelson tyrosine-protein kinase 2 (Abl2), as required for efficient SARS-CoV and MERS-CoV replication in vitro. These data demonstrate that specific approved drugs can be characterized in vitro for their anticoronavirus activity and used to identify host proteins required for coronavirus replication. This type of study is an important step in the repurposing of approved drugs for treatment of emerging coronaviruses. IMPORTANCE Both SARS-CoV and MERS-CoV are zoonotic infections, with bats as the primary source. The 2003 SARS-CoV outbreak began in Guangdong Province in China and spread to humans via civet cats and raccoon dogs in the wet markets before spreading to 37 countries. The virus caused 8,096 confirmed cases of SARS and 774 deaths (a case fatality rate of ∼10%). The MERS-CoV outbreak began in Saudi Arabia and has spread to 27 countries. MERS-CoV is believed to have emerged from bats and passed into humans via camels. The ongoing outbreak of MERS-CoV has resulted in 1,791 cases of MERS and 640 deaths (a case fatality rate of 36%). The emergence of SARS-CoV and MERS-CoV provides evidence that coronaviruses are currently spreading from zoonotic

  7. Unprecedently Large-Scale Kinase Inhibitor Set Enabling the Accurate Prediction of Compound–Kinase Activities: A Way toward Selective Promiscuity by Design?

    PubMed Central

    2016-01-01

    Drug discovery programs frequently target members of the human kinome and try to identify small molecule protein kinase inhibitors, primarily for cancer treatment, additional indications being increasingly investigated. One of the challenges is controlling the inhibitors degree of selectivity, assessed by in vitro profiling against panels of protein kinases. We manually extracted, compiled, and standardized such profiles published in the literature: we collected 356 908 data points corresponding to 482 protein kinases, 2106 inhibitors, and 661 patents. We then analyzed this data set in terms of kinome coverage, results reproducibility, popularity, and degree of selectivity of both kinases and inhibitors. We used the data set to create robust proteochemometric models capable of predicting kinase activity (the ligand–target space was modeled with an externally validated RMSE of 0.41 ± 0.02 log units and R02 0.74 ± 0.03), in order to account for missing or unreliable measurements. The influence on the prediction quality of parameters such as number of measurements, Murcko scaffold frequency or inhibitor type was assessed. Interpretation of the models enabled to highlight inhibitors and kinases properties correlated with higher affinities, and an analysis in the context of kinases crystal structures was performed. Overall, the models quality allows the accurate prediction of kinase-inhibitor activities and their structural interpretation, thus paving the way for the rational design of compounds with a targeted selectivity profile. PMID:27482722

  8. Structure and inhibitor specificity of the PCTAIRE-family kinase CDK16

    PubMed Central

    Dixon-Clarke, Sarah E.; Shehata, Saifeldin N.; Krojer, Tobias; Sharpe, Timothy D.; vonDelft, Frank; Sakamoto, Kei

    2017-01-01

    CDK16 (also known as PCTAIRE1 or PCTK1) is an atypical member of the cyclin-dependent kinase (CDK) family that has emerged as a key regulator of neurite outgrowth, vesicle trafficking and cancer cell proliferation. CDK16 is activated through binding to cyclin Y via a phosphorylation-dependent 14-3-3 interaction and has a unique consensus substrate phosphorylation motif compared with conventional CDKs. To elucidate the structure and inhibitor-binding properties of this atypical CDK, we screened the CDK16 kinase domain against different inhibitor libraries and determined the co-structures of identified hits. We discovered that the ATP-binding pocket of CDK16 can accommodate both type I and type II kinase inhibitors. The most potent CDK16 inhibitors revealed by cell-free and cell-based assays were the multitargeted cancer drugs dabrafenib and rebastinib. An inactive DFG-out binding conformation was confirmed by the first crystal structures of CDK16 in separate complexes with the inhibitors indirubin E804 and rebastinib, respectively. The structures revealed considerable conformational plasticity, suggesting that the isolated CDK16 kinase domain was relatively unstable in the absence of a cyclin partner. The unusual structural features and chemical scaffolds identified here hold promise for the development of more selective CDK16 inhibitors and provide opportunity to better characterise the role of CDK16 and its related CDK family members in various physiological and pathological contexts. PMID:28057719

  9. Activation of Pim Kinases Is Sufficient to Promote Resistance to MET Small Molecule Inhibitors

    PubMed Central

    An, Ningfei; Xiong, Ying; LaRue, Amanda C.; Kraft, Andrew S.; Cen, Bo

    2015-01-01

    MET blockade offers a new targeted therapy particularly in those cancers with MET amplification. However, the efficacy and the duration of the response to MET inhibitors are limited by the emergence of drug resistance. Here we report that resistance to small molecule inhibitors of MET can arise from increased expression of the pro-survival Pim protein kinases. This resistance mechanism was documented in non-small cell lung cancer and gastric cancer cells with MET amplification. Inhibition of Pim kinases enhanced cell death triggered by short-term treatment with MET inhibitors. Pim kinases control the translation of anti-apoptotic protein Bcl-2 at an internal ribosome entry site and this mechanism was identified as the basis for Pim-mediated resistance to MET inhibitors. Protein synthesis was increased in drug-resistant cells, secondary to a Pim-mediated increase in cap-independent translation. In cells rendered drug resistant by chronic treatment with MET inhibitors, genetic or pharmacological inhibition of Pim kinases was sufficient to restore sensitivity in vitro and in vivo. Taken together, our results rationalize Pim inhibition as a strategy to augment responses and blunt acquired resistance to MET inhibitors in cancer. PMID:26670562

  10. Structure and inhibitor specificity of the PCTAIRE-family kinase CDK16.

    PubMed

    Dixon-Clarke, Sarah E; Shehata, Saifeldin N; Krojer, Tobias; Sharpe, Timothy D; von Delft, Frank; Sakamoto, Kei; Bullock, Alex N

    2017-02-20

    CDK16 (also known as PCTAIRE1 or PCTK1) is an atypical member of the cyclin-dependent kinase (CDK) family that has emerged as a key regulator of neurite outgrowth, vesicle trafficking and cancer cell proliferation. CDK16 is activated through binding to cyclin Y via a phosphorylation-dependent 14-3-3 interaction and has a unique consensus substrate phosphorylation motif compared with conventional CDKs. To elucidate the structure and inhibitor-binding properties of this atypical CDK, we screened the CDK16 kinase domain against different inhibitor libraries and determined the co-structures of identified hits. We discovered that the ATP-binding pocket of CDK16 can accommodate both type I and type II kinase inhibitors. The most potent CDK16 inhibitors revealed by cell-free and cell-based assays were the multitargeted cancer drugs dabrafenib and rebastinib. An inactive DFG-out binding conformation was confirmed by the first crystal structures of CDK16 in separate complexes with the inhibitors indirubin E804 and rebastinib, respectively. The structures revealed considerable conformational plasticity, suggesting that the isolated CDK16 kinase domain was relatively unstable in the absence of a cyclin partner. The unusual structural features and chemical scaffolds identified here hold promise for the development of more selective CDK16 inhibitors and provide opportunity to better characterise the role of CDK16 and its related CDK family members in various physiological and pathological contexts.

  11. Aurora kinase inhibitors--rising stars in cancer therapeutics?

    PubMed

    Dar, Altaf A; Goff, Laura W; Majid, Shahana; Berlin, Jordan; El-Rifai, Wael

    2010-02-01

    Standard therapeutic approaches of cytotoxics and radiation in cancer are not only highly toxic, but also of limited efficacy in treatment of a significant number of cancer patients. The molecular analysis of the cancer genomes have shown a remarkable complexity and pointed to key genomic and epigenomic alterations in cancer. These discoveries are paving the way for targeted therapy approaches. However, although there are a large number of potential targets, only a few can regulate key cellular functions and intersect multiple signaling networks. The Aurora kinase family members (A, B, and C) are a collection of highly related and conserved serine-threonine kinases that fulfill these criteria, being key regulators of mitosis and multiple signaling pathways. Alterations in Aurora kinase signaling are associated with mitotic errors and have been closely linked to chromosomal aneuploidy in cancer cells. Several studies have shown amplification and/or overexpression of Aurora kinase A and B in hematologic malignancies and solid tumors. Over the past several years, Aurora kinases have become attractive targets. Several ongoing clinical trials and bench-based research are assessing the unique therapeutic potential of Aurora-based targeted therapy.

  12. A novel transmembrane Ser/Thr kinase complexes with protein phosphatase-1 and inhibitor-2.

    PubMed

    Wang, Hong; Brautigan, David L

    2002-12-20

    Protein kinases and protein phosphatases exert coordinated control over many essential cellular processes. Here, we describe the cloning and characterization of a novel human transmembrane protein KPI-2 (Kinase/Phosphatase/Inhibitor-2) that was identified by yeast two-hybrid using protein phosphatase inhibitor-2 (Inh2) as bait. KPI-2 mRNA was predominantly expressed in skeletal muscle. KPI-2 is a 1503-residue protein with two predicted transmembrane helices at the N terminus, a kinase domain, followed by a C-terminal domain. The transmembrane helices were sufficient for targeting proteins to the membrane. KPI-2 kinase domain has about 60% identity with its closest relative, a tyrosine kinase. However, it only exhibited serine/threonine kinase activity in autophosphorylation reactions or with added substrates. KPI-2 kinase domain phosphorylated protein phosphatase-1 (PP1C) at Thr(320), which attenuated PP1C activity. KPI-2 C-terminal domain directly associated with PP1C, and this required a VTF motif. Inh2 associated with KPI-2 C-terminal domain with and without PP1C. Thus, KPI-2 is a kinase with sites to associate with PP1C and Inh2 to form a regulatory complex that is localized to membranes.

  13. Structural insight into selectivity and resistance profiles of ROS1 tyrosine kinase inhibitors

    PubMed Central

    Davare, Monika A.; Vellore, Nadeem A.; Wagner, Jacob P.; Eide, Christopher A.; Goodman, James R.; Drilon, Alexander; Deininger, Michael W.; O’Hare, Thomas; Druker, Brian J.

    2015-01-01

    Oncogenic ROS1 fusion proteins are molecular drivers in multiple malignancies, including a subset of non-small cell lung cancer (NSCLC). The phylogenetic proximity of the ROS1 and anaplastic lymphoma kinase (ALK) catalytic domains led to the clinical repurposing of the Food and Drug Administration (FDA)-approved ALK inhibitor crizotinib as a ROS1 inhibitor. Despite the antitumor activity of crizotinib observed in both ROS1- and ALK-rearranged NSCLC patients, resistance due to acquisition of ROS1 or ALK kinase domain mutations has been observed clinically, spurring the development of second-generation inhibitors. Here, we profile the sensitivity and selectivity of seven ROS1 and/or ALK inhibitors at various levels of clinical development. In contrast to crizotinib’s dual ROS1/ALK activity, cabozantinib (XL-184) and its structural analog foretinib (XL-880) demonstrate a striking selectivity for ROS1 over ALK. Molecular dynamics simulation studies reveal structural features that distinguish the ROS1 and ALK kinase domains and contribute to differences in binding site and kinase selectivity of the inhibitors tested. Cell-based resistance profiling studies demonstrate that the ROS1-selective inhibitors retain efficacy against the recently reported CD74-ROS1G2032R mutant whereas the dual ROS1/ALK inhibitors are ineffective. Taken together, inhibitor profiling and stringent characterization of the structure–function differences between the ROS1 and ALK kinase domains will facilitate future rational drug design for ROS1- and ALK-driven NSCLC and other malignancies. PMID:26372962

  14. 3-Cyano-6-(5-methyl-3-pyrazoloamino) pyridines (Part 2): A dual inhibitor of Aurora kinase and tubulin polymerization.

    PubMed

    Morioka, Masahiko

    2016-12-15

    A new class of a dual inhibitor of Aurora kinase and tubulin polymerization was created by introducing various substituted phenoxyethylamino or pyridyloxyethylamino groups to the 2-position of 3-cyano-4-methyl-6-(5-methyl-3-pyrazoloamino)-pyridine. Compound 3g exhibited Aurora kinase inhibition, excellent protein kinase selectivity to Aurora kinase in comparison with 66 other kinases, inhibition of phosphorylation of Ser10 of histone H3 as an Aurora kinase inhibitor, inhibition of tubulin polymerization in vitro, good cell membrane permeability, and a good PK profile. Therefore compound 3g was effective in some antitumor mouse models at a dose of 30mg/kgpoqd.

  15. Discovery of Small Molecule Mer Kinase Inhibitors for the Treatment of Pediatric Acute Lymphoblastic Leukemia

    PubMed Central

    2012-01-01

    Ectopic Mer expression promotes pro-survival signaling and contributes to leukemogenesis and chemoresistance in childhood acute lymphoblastic leukemia (ALL). Consequently, Mer kinase inhibitors may promote leukemic cell death and further act as chemosensitizers increasing efficacy and reducing toxicities of current ALL regimens. We have applied a structure-based design approach to discover novel small molecule Mer kinase inhibitors. Several pyrazolopyrimidine derivatives effectively inhibit Mer kinase activity at subnanomolar concentrations. Furthermore, the lead compound shows a promising selectivity profile against a panel of 72 kinases and has excellent pharmacokinetic properties. We also describe the crystal structure of the complex between the lead compound and Mer, opening new opportunities for further optimization and new template design. PMID:22662287

  16. Discovery of Novel Small Molecule Mer Kinase Inhibitors for the Treatment of Pediatric Acute Lymphoblastic Leukemia.

    PubMed

    Liu, Jing; Yang, Chao; Simpson, Catherine; Deryckere, Deborah; Van Deusen, Amy; Miley, Michael J; Kireev, Dmitri; Norris-Drouin, Jacqueline; Sather, Susan; Hunter, Debra; Korboukh, Victoria K; Patel, Hari S; Janzen, William P; Machius, Mischa; Johnson, Gary L; Earp, H Shelton; Graham, Douglas K; Frye, Stephen V; Wang, Xiaodong

    2012-02-09

    Ectopic Mer expression promotes pro-survival signaling and contributes to leukemogenesis and chemoresistance in childhood acute lymphoblastic leukemia (ALL). Consequently, Mer kinase inhibitors may promote leukemic cell death and further act as chemosensitizers increasing efficacy and reducing toxicities of current ALL regimens. We have applied a structure-based design approach to discover novel small molecule Mer kinase inhibitors. Several pyrazolopyrimidine derivatives effectively inhibit Mer kinase activity at sub-nanomolar concentrations. Furthermore, the lead compound shows a promising selectivity profile against a panel of 72 kinases and has excellent pharmacokinetic properties. We also describe the crystal structure of the complex between the lead compound and Mer, opening new opportunities for further optimization and new template design.

  17. Recent advances in the development of Aurora kinases inhibitors in hematological malignancies.

    PubMed

    Choudary, Iqra; Barr, Paul M; Friedberg, Jonathan

    2015-12-01

    Over the last two decades, since the discovery of Drosophila mutants in 1995, much effort has been made to understand Aurora kinase biology. Three mammalian subtypes have been identified thus far which include the Aurora A, B and C kinases. These regulatory proteins specifically work at the cytoskeleton and chromosomal structures between the kinetochores and have vital functions in the early phases of the mitotic cell cycle. Today, there are multiple phase I and phase II clinical trials as well as numerous preclinical studies taking place looking at Aurora kinase inhibitors in both hematologic and solid malignancies. This review focuses on the preclinical and clinical development of Aurora kinase inhibitors in hematological malignancy and discusses their therapeutic potential.

  18. Recent advances in the development of Aurora kinases inhibitors in hematological malignancies

    PubMed Central

    Choudary, Iqra; Barr, Paul M.; Friedberg, Jonathan

    2015-01-01

    Over the last two decades, since the discovery of Drosophila mutants in 1995, much effort has been made to understand Aurora kinase biology. Three mammalian subtypes have been identified thus far which include the Aurora A, B and C kinases. These regulatory proteins specifically work at the cytoskeleton and chromosomal structures between the kinetochores and have vital functions in the early phases of the mitotic cell cycle. Today, there are multiple phase I and phase II clinical trials as well as numerous preclinical studies taking place looking at Aurora kinase inhibitors in both hematologic and solid malignancies. This review focuses on the preclinical and clinical development of Aurora kinase inhibitors in hematological malignancy and discusses their therapeutic potential. PMID:26622997

  19. Lichen planopilaris-like eruption during treatment with tyrosine kinase inhibitor nilotinib*

    PubMed Central

    Leitão, Juliana Ribeiro; Valente, Neusa Yuriko Sakai; Kakizaki, Priscila; Veronez, Isis Suga; Pires, Mario Cezar

    2016-01-01

    Tyrosine kinase inhibitors are effective as a target therapy for malignant neoplasms. Imatinib was the first tyrosine kinase inhibitor used. After its introduction, several other drugs have appeared with a similar mechanism of action, but less prone to causing resistance. Even though these drugs are selective, their toxicity does not exclusively target cancer cells, and skin toxicity is the most common non-hematologic adverse effect. We report an eruption similar to lichen planopilaris that developed during therapy with nilotinib, a second generation tyrosine kinase inhibitor, in a patient with chronic myeloid leukemia resistant to imatinib. In a literature review, we found only one report of non-scarring alopecia due to the use of nilotinib.

  20. Method for distinguishing normal and transformed cells using G1 kinase inhibitors

    DOEpatents

    Crissman, Harry A.; Gadbois, Donna M.; Tobey, Robert A.; Bradbury, E. Morton

    1993-01-01

    A G.sub.1 phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G.sub.1 phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G.sub.1 cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G.sub.1 phase, suggesting that such G.sub.1 phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

  1. Science Signaling Podcast for 15 November 2016: A new type of kinase inhibitor.

    PubMed

    Eldar-Finkelman, Hagit; VanHook, Annalisa M

    2016-11-15

    This Podcast features an interview with Hagit Eldar-Finkelman, author of a Research Article that appears in the 15 November 2016 issue of Science Signaling, about a newly developed inhibitor of glycogen synthase kinase 3 (GSK-3). GSK-3 participates in several signaling networks and has been implicated in various pathologies, including neurodegenerative diseases, cognitive impairments, and cancer. Licht-Murava et al developed L807mts, a substrate-competitive peptide inhibitor that blocks GSK-3 activity through an unusual mechanism. L807mts not only bound to the substrate recognition domain of GSK-3, it was also phosphorylated by the kinase. This phosphorylated form of L807mts remained associated with GSK-3 and inhibited GSK-3 activity. L807mts treatment reduced cellular, cognitive, and behavioral symptoms in a mouse model of Alzheimer's disease. L807mts is an advance in kinase inhibitor development because it is both highly specific and very potent.Listen to Podcast.

  2. Method for distinguishing normal and transformed cells using G1 kinase inhibitors

    DOEpatents

    Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.

    1993-02-09

    A G[sub 1] phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G[sub 1] phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G[sub 1] cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G[sub 1] phase, suggesting that such G[sub 1] phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

  3. Method for distinguishing normal and transformed cells using G1 kinase inhibitors

    SciTech Connect

    Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.

    1991-12-31

    A G{sub 1} phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G{sub 1} phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G{sub 1} cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G{sub 1} phase, suggesting that such G{sub 1} phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

  4. A first generation inhibitor of human Greatwall kinase, enabled by structural and functional characterisation of a minimal kinase domain construct

    PubMed Central

    Ocasio, Cory A.; Rajasekaran, Mohan B.; Walker, Sarah; Le Grand, Darren; Spencer, John; Pearl, Frances M.G.; Ward, Simon E.; Savic, Velibor; Pearl, Laurence H.; Hochegger, Helfrid; Oliver, Antony W.

    2016-01-01

    MASTL (microtubule-associated serine/threonine kinase-like), more commonly known as Greatwall (GWL), has been proposed as a novel cancer therapy target. GWL plays a crucial role in mitotic progression, via its known substrates ENSA/ARPP19, which when phosphorylated inactivate PP2A/B55 phosphatase. When over-expressed in breast cancer, GWL induces oncogenic properties such as transformation and invasiveness. Conversely, down-regulation of GWL selectively sensitises tumour cells to chemotherapy. Here we describe the first structure of the GWL minimal kinase domain and development of a small-molecule inhibitor GKI-1 (Greatwall Kinase Inhibitor-1). In vitro, GKI-1 inhibits full-length human GWL, and shows cellular efficacy. Treatment of HeLa cells with GKI-1 reduces ENSA/ARPP19 phosphorylation levels, such that they are comparable to those obtained by siRNA depletion of GWL; resulting in a decrease in mitotic events, mitotic arrest/cell death and cytokinesis failure. Furthermore, GKI-1 will be a useful starting point for the development of more potent and selective GWL inhibitors. PMID:27563826

  5. "Addition" and "Subtraction": Selectivity Design for Type II Maternal Embryonic Leucine Zipper Kinase Inhibitors.

    PubMed

    Chen, Xin; Giraldes, John; Sprague, Elizabeth R; Shakya, Subarna; Chen, Zhuoliang; Wang, Yaping; Joud, Carol; Mathieu, Simon; Chen, Christine Hiu-Tung; Straub, Christopher; Duca, Jose; Hurov, Kristen; Yuan, Yanqiu; Shao, Wenlin; Touré, B Barry

    2017-03-09

    While adding the structural features that are more favored by on-target activity is the more common strategy in selectivity optimization, the opposite strategy of subtracting the structural features that contribute more to off-target activity can also be very effective. Reported here is our successful effort of improving the kinase selectivity of type II maternal embryonic leucine zipper kinase inhibitors by applying these two complementary approaches together, which clearly demonstrates the powerful synergy between them.

  6. Chemical inhibitors of c-Met receptor tyrosine kinase stimulate osteoblast differentiation and bone regeneration.

    PubMed

    Kim, Jung-Woo; Nam Lee, Mi; Jeong, Byung-Chul; Oh, Sin-Hye; Kook, Min-Suk; Koh, Jeong-Tae

    2017-03-16

    The c-Met receptor tyrosine kinase and its ligand, hepatocyte growth factor (HGF), have been recently introduced to negatively regulate bone morphogenetic protein (BMP)-induced osteogenesis. However, the effect of chemical inhibitors of c-Met receptor on osteoblast differentiation process has not been examined, especially the applicability of c-Met chemical inhibitors on in vivo bone regeneration. In this study, we demonstrated that chemical inhibitors of c-Met receptor tyrosine kinase, SYN1143 and SGX523, could potentiate the differentiation of precursor cells to osteoblasts and stimulate regeneration in calvarial bone defects of mice. Treatment with SYN1143 or SGX523 inhibited HGF-induced c-Met phosphorylation in MC3T3-E1 and C3H10T1/2 cells. Cell proliferation of MC3T3-E1 or C3H10T1/2 was not significantly affected by the concentrations of these inhibitors. Co-treatment with chemical inhibitor of c-Met and osteogenic inducing media enhanced osteoblast-specific genes expression and calcium nodule formation accompanied by increased Runx2 expression via c-Met receptor-dependent but Erk-Smad signaling independent pathway. Notably, the administration of these c-Met inhibitors significantly repaired critical-sized calvarial bone defects. Collectively, our results suggest that chemical inhibitors of c-Met receptor tyrosine kinase might be used as novel therapeutics to induce bone regeneration.

  7. Are Accurins the cure for Aurora kinase inhibitors?

    PubMed

    Bearss, David J

    2016-02-10

    A nanoparticle formulation of an Aurora B inhibitor increases antitumor efficacy and reduces toxicity, which may be a precedent for the use of this technology with other small molecules (Ashton et al., this issue).

  8. Crystal structures of the S6K1 kinase domain in complexes with inhibitors.

    PubMed

    Niwa, Hideaki; Mikuni, Junko; Sasaki, Shunta; Tomabechi, Yuri; Honda, Keiko; Ikeda, Mariko; Ohsawa, Noboru; Wakiyama, Motoaki; Handa, Noriko; Shirouzu, Mikako; Honma, Teruki; Tanaka, Akiko; Yokoyama, Shigeyuki

    2014-09-01

    Ribosomal protein S6 kinase 1 (S6K1) is a serine/threonine protein kinase that plays an important role in the PIK3/mTOR signaling pathway, and is implicated in diseases including diabetes, obesity, and cancer. The crystal structures of the S6K1 kinase domain in complexes with staurosporine and the S6K1-specific inhibitor PF-4708671 have been reported. In the present study, five compounds (F108, F109, F176, F177, and F179) were newly identified by in silico screening of a chemical library and kinase assay. The crystal structures of the five inhibitors in complexes with the S6K1 kinase domain were determined at resolutions between 1.85 and 2.10 Å. All of the inhibitors bound to the ATP binding site, lying along the P-loop, while the activation loop stayed in the inactive form. Compound F179, with a carbonyl group in the middle of the molecule, altered the αC helix conformation by interacting with the invariant Lys123. Compounds F176 and F177 bound slightly distant from the hinge region, and their sulfoamide groups formed polar interactions with the protein. The structural features required for the specific binding of inhibitors are discussed.

  9. Targeting kinases with anilinopyrimidines: discovery of N-phenyl-N’-[4-(pyrimidin-4-ylamino)phenyl]urea derivatives as selective inhibitors of class III receptor tyrosine kinase subfamily

    PubMed Central

    Gandin, Valentina; Ferrarese, Alessandro; Dalla Via, Martina; Marzano, Cristina; Chilin, Adriana; Marzaro, Giovanni

    2015-01-01

    Kinase inhibitors are attractive drugs/drug candidates for the treatment of cancer. The most recent literature has highlighted the importance of multi target kinase inhibitors, although a correct balance between specificity and non-specificity is required. In this view, the discovery of multi-tyrosine kinase inhibitors with subfamily selectivity is a challenging goal. Herein we present the synthesis and the preliminary kinase profiling of a set of novel 4-anilinopyrimidines. Among the synthesized compounds, the N-phenyl-N’-[4-(pyrimidin-4-ylamino)phenyl]urea derivatives selectively targeted some members of class III receptor tyrosine kinase family. Starting from the structure of hit compound 19 we synthesized a further compound with an improved affinity toward the class III receptor tyrosine kinase members and endowed with a promising antitumor activity both in vitro and in vivo in a murine solid tumor model. Molecular modeling simulations were used in order to rationalize the behavior of the title compounds. PMID:26568452

  10. Targeting the TGF-β receptor with kinase inhibitors for scleroderma therapy.

    PubMed

    Cong, Lin; Xia, Zhi-Kuan; Yang, Rong-Ya

    2014-09-01

    Scleroderma (systemic sclerosis) is a connective tissue disease that affects various organ systems; the treatment of scleroderma is still difficult and remains a challenge to the clinician. Recently, kinase inhibitors have shown great potential against fibrotic diseases and, specifically, the transforming growth factor-β receptor (TGF-βR) was found as a new and promising target for scleroderma therapy. In the current study, we propose that the large pool of existing kinase inhibitors could be exploited for inhibiting the TGF-βR to suppress scleroderma. In this respect, we developed a modeling protocol to systematically profile the inhibitory activities of 169 commercially available kinase inhibitors against the TGF-βR, from which five promising candidates were selected and tested using a standard kinase assay protocol. Consequently, two molecular entities, namely the PKB inhibitor MK-2206 and the mTOR C1/C2 inhibitor AZD8055, showed high potency when bound to the TGF-βR, with IC50 values of 97 and 86 nM, respectively, which are close to those of the recently developed TGF-βR selective inhibitors SB525334 and LY2157299 (IC50 = 14.3 and 56 nM, respectively). We also performed atomistic molecular dynamics simulations and post-molecular mechanics/Poisson-Boltzmann surface area analyses to dissect the structural basis and energetic properties of intermolecular interactions between the TGF-βR kinase domain and these potent compounds, highlighting intensive nonbonded networks across the tightly packed interface of non-cognate TGF-βR-inhibitor complexes.

  11. Preclinical testing of selective Aurora kinase inhibitors on a medullary thyroid carcinoma-derived cell line.

    PubMed

    Tuccilli, Chiara; Baldini, Enke; Prinzi, Natalie; Morrone, Stefania; Sorrenti, Salvatore; Filippini, Angelo; Catania, Antonio; Alessandrini, Stefania; Rendina, Roberta; Coccaro, Carmela; D'Armiento, Massimino; Ulisse, Salvatore

    2016-05-01

    Deregulated expression of the Aurora kinases (Aurora-A, B, and C) is thought to be involved in cell malignant transformation and genomic instability in several cancer types. Over the last decade, a number of small-molecule inhibitors of Aurora kinases have been developed, which have proved to efficiently restrain malignant cell growth and tumorigenicity. Regarding medullary thyroid carcinoma (MTC), we previously showed the efficacy of a pan-Aurora kinase inhibitor (MK-0457) in impairing growth and survival of the MTC-derived cell line TT. In the present study, we sought to establish if one of the Aurora kinases might represent a preferential target for MTC therapy. The effects of selective inhibitors of Aurora-A (MLN8237) and Aurora-B (AZD1152) were analyzed on TT cell proliferation, apoptosis, cell cycle, and ploidy. The two inhibitors reduced TT cell proliferation in a time- and dose-dependent manner, with IC50 of 19.0 ± 2.4 nM for MLN8237 and 401.6 ± 44.1 nM for AZD1152. Immunofluorescence experiments confirmed that AZD1152 inhibited phosphorylation of histone H3 (Ser10) by Aurora-B, while it did not affect Aurora-A autophosphorylation. MLN8237 inhibited Aurora-A autophosphorylation as expected, but at concentrations required to achieve the maximum antiproliferative effects it also abolished H3 (Ser10) phosphorylation. Cytofluorimetry experiments showed that both inhibitors induced accumulation of cells in G2/M phase and increased the subG0/G1 fraction and polyploidy. Finally, both inhibitors triggered apoptosis. We demonstrated that inhibition of either Aurora-A or Aurora-B has antiproliferative effects on TT cells, and thus it would be worthwhile to further investigate the therapeutical potential of Aurora kinase inhibitors in MTC treatment.

  12. The Abl and Arg non-receptor tyrosine kinases regulate different zones of stress fiber, focal adhesion, and contractile network localization in spreading fibroblasts.

    PubMed

    Peacock, Justin G; Couch, Brian A; Koleske, Anthony J

    2010-10-01

    Directed cell migration requires precise spatial control of F-actin-based leading edge protrusion, focal adhesion (FA) dynamics, and actomyosin contractility. In spreading fibroblasts, the Abl family kinases, Abl and Arg, primarily localize to the nucleus and cell periphery, respectively. Here we provide evidence that Abl and Arg exert different spatial regulation on cellular contractile and adhesive structures. Loss of Abl function reduces FA, F-actin, and phosphorylated myosin light chain (pMLC) staining at the cell periphery, shifting the distribution of these elements more to the center of the cell than in wild-type (WT) and arg(-/-) cells. Conversely, loss of Arg function shifts the distribution of these contractile and adhesion elements more to the cell periphery relative to WT and abl(-/-) cells. Abl/Arg-dependent phosphorylation of p190RhoGAP (p190) promotes its binding to p120RasGAP (p120) to form a functional RhoA GTPase inhibitory complex, which attenuates RhoA activity and downstream pMLC and FA formation. p120 and p190 colocalize both in the central region and at the cell periphery in WT cells. This p120:p190 colocalization redistributes to a more peripheral distribution in abl(-/-) cells and to a more centralized distribution in arg(-/-) cells, and these altered distributions can be restored to WT patterns via re-expression of Abl or Arg, respectively. Thus, the altered p120:p190 distribution in the mutant cells correlates inversely with the redistribution in adhesions, actin, and pMLC staining in these cells. Our studies suggest that Abl and Arg exert different spatial regulation on actomyosin contractility and focal adhesions within cells.

  13. A novel Pim-1 kinase inhibitor targeting residues that bind the substrate peptide.

    PubMed

    Tsuganezawa, Keiko; Watanabe, Hisami; Parker, Lorien; Yuki, Hitomi; Taruya, Shigenao; Nakagawa, Yukari; Kamei, Daisuke; Mori, Masumi; Ogawa, Naoko; Tomabechi, Yuri; Handa, Noriko; Honma, Teruki; Yokoyama, Shigeyuki; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Tanaka, Akiko

    2012-03-30

    A new screening method using fluorescent correlation spectroscopy was developed to select kinase inhibitors that competitively inhibit the binding of a fluorescently labeled substrate peptide. Using the method, among approximately 700 candidate compounds selected by virtual screening, we identified a novel Pim-1 kinase inhibitor targeting its peptide binding residues. X-ray crystal analysis of the complex structure of Pim-1 with the inhibitor indicated that the inhibitor actually binds to the ATP-binding site and also forms direct interactions with residues (Asp128 and Glu171) that bind the substrate peptide. These interactions, which cause small side-chain movements, seem to affect the binding ability of the fluorescently labeled substrate. The compound inhibited Pim-1 kinase in vitro, with an IC(50) value of 150 nM. Treatment of cultured leukemia cells with the compound reduced the amount of p21 and increased the amount of p27, due to Pim-1 inhibition, and then triggered apoptosis after cell-cycle arrest at the G(1)/S phase. This screening method may be widely applicable for the identification of various new Pim-1 kinase inhibitors targeting the residues that bind the substrate peptide.

  14. Inhibitors of cellular kinases with broad-spectrum antiviral activity for hemorrhagic fever viruses.

    PubMed

    Mohr, Emma L; McMullan, Laura K; Lo, Michael K; Spengler, Jessica R; Bergeron, Éric; Albariño, César G; Shrivastava-Ranjan, Punya; Chiang, Cheng-Feng; Nichol, Stuart T; Spiropoulou, Christina F; Flint, Mike

    2015-08-01

    Host cell kinases are important for the replication of a number of hemorrhagic fever viruses. We tested a panel of kinase inhibitors for their ability to block the replication of multiple hemorrhagic fever viruses. OSU-03012 inhibited the replication of Lassa, Ebola, Marburg and Nipah viruses, whereas BIBX 1382 dihydrochloride inhibited Lassa, Ebola and Marburg viruses. BIBX 1382 blocked both Lassa and Ebola virus glycoprotein-dependent cell entry. These compounds may be used as tools to understand conserved virus-host interactions, and implicate host cell kinases that may be targets for broad spectrum therapeutic intervention.

  15. Development of Certain Protein Kinase Inhibitors with the Components from Traditional Chinese Medicine

    PubMed Central

    Liu, Minghua; Zhao, Ge; Cao, Shousong; Zhang, Yangyang; Li, Xiaofang; Lin, Xiukun

    2017-01-01

    Traditional Chinese medicines (TCMs) have been used in China for more than two thousand years, and some of them have been confirmed to be effective in cancer treatment. Protein kinases play critical roles in control of cell growth, proliferation, migration, survival, and angiogenesis and mediate their biological effects through their catalytic activity. In recent years, numerous protein kinase inhibitors have been developed and are being used clinically. Anticancer TCMs represent a large class of bioactive substances, and some of them display anticancer activity via inhibiting protein kinases to affect the phosphoinositide 3-kinase, serine/threonine-specific protein kinases, pechanistic target of rapamycin (PI3K/AKT/mTOR), P38, mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) pathways. In the present article, we comprehensively reviewed several components isolated from anticancer TCMs that exhibited significantly inhibitory activity toward a range of protein kinases. These components, which belong to diverse structural classes, are reviewed herein, based upon the kinases that they inhibit. The prospects and problems in development of the anticancer TCMs are also discussed. PMID:28119606

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

    DOEpatents

    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.

  17. Selective inhibitors of Cyclin-G associated kinase (GAK) as anti-HCV agents

    PubMed Central

    Kovackova, Sona; Chang, Lei; Bekerman, Elena; Neveu, Gregory; Barouch-Bentov, Rina; Chaikuad, Apirat; Heroven, Christina; Šála, Michal; De Jonghe, Steven; Knapp, Stefan; Einav, Shirit; Herdewijn, Piet

    2015-01-01

    Cyclin-G associated kinase (GAK) emerged as a promising drug target for the treatment of viral infections. However, no potent and selective GAK inhibitors have been reported in the literature to date. This paper describes the discovery of isothiazolo[5,4-b]pyridines as selective GAK inhibitors, with the most potent congeners displaying low nanomolar binding affinity for GAK. Co-crystallization experiments revealed that these compounds behaved as classic type I ATP-competitive kinase inhibitors. In addition, we have demonstrated that these compounds exhibit a potent activity against hepatitis C virus (HCV) by inhibiting two temporally distinct steps in the HCV lifecycle (i.e. viral entry and assembly). Hence, these GAK inhibitors represent chemical probes to study GAK function in different disease areas where GAK has been implicated (including viral infection, cancer and Parkinson's disease). PMID:25822739

  18. Shaping development of autophagy inhibitors with the structure of the lipid kinase Vps34.

    PubMed

    Miller, Simon; Tavshanjian, Brandon; Oleksy, Arkadiusz; Perisic, Olga; Houseman, Benjamin T; Shokat, Kevan M; Williams, Roger L

    2010-03-26

    Phosphoinositide 3-kinases (PI3Ks) are lipid kinases with diverse roles in health and disease. The primordial PI3K, Vps34, is present in all eukaryotes and has essential roles in autophagy, membrane trafficking, and cell signaling. We solved the crystal structure of Vps34 at 2.9 angstrom resolution, which revealed a constricted adenine-binding pocket, suggesting the reason that specific inhibitors of this class of PI3K have proven elusive. Both the phosphoinositide-binding loop and the carboxyl-terminal helix of Vps34 mediate catalysis on membranes and suppress futile adenosine triphosphatase cycles. Vps34 appears to alternate between a closed cytosolic form and an open form on the membrane. Structures of Vps34 complexes with a series of inhibitors reveal the reason that an autophagy inhibitor preferentially inhibits Vps34 and underpin the development of new potent and specific Vps34 inhibitors.

  19. Aurora A Kinase Inhibitor AKI603 Induces Cellular Senescence in Chronic Myeloid Leukemia Cells Harboring T315I Mutation

    PubMed Central

    Wang, Le-Xun; Wang, Jun-Dan; Chen, Jia-Jie; Long, Bing; Liu, Ling-Ling; Tu, Xi-Xiang; Luo, Yu; Hu, Yuan; Lin, Dong-Jun; Lu, Gui; Long, Zi-Jie; Liu, Quentin

    2016-01-01

    The emergence of resistance to imatinib mediated by mutations in the BCR-ABL has become a major challenge in the treatment of chronic myeloid leukemia (CML). Alternative therapeutic strategies to override imatinib-resistant CML are urgently needed. In this study, we investigated the effect of AKI603, a novel small molecule inhibitor of Aurora kinase A (AurA) to overcome resistance mediated by BCR-ABL-T315I mutation. Our results showed that AKI603 exhibited strong anti-proliferative activity in leukemic cells. AKI603 inhibited cell proliferation and colony formation capacities in imatinib-resistant CML cells by inducing cell cycle arrest with polyploidy accumulation. Surprisingly, inhibition of AurA by AKI603 induced leukemia cell senescence in both BCR-ABL wild type and T315I mutation cells. Furthermore, the induction of senescence was associated with enhancing reactive oxygen species (ROS) level. Moreover, the anti-tumor effect of AKI603 was proved in the BALB/c nude mice KBM5-T315I xenograft model. Taken together, our data demonstrate that the small molecule AurA inhibitor AKI603 may be used to overcome drug resistance induced by BCR-ABL-T315I mutation in CML. PMID:27824120

  20. Novel inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase.

    PubMed

    El-Sayed, Mardia Telep; Zoraghi, Roya; Reiner, Neil; Suzen, Sibel; Ohlsen, Knut; Lalk, Michael; Altanlar, Nurten; Hilgeroth, Andreas

    2016-12-01

    Novel bisindolyl-cycloalkane indoles resulted from the reaction of aliphatic dialdehydes and indole. As bisindolyl-natural alkaloid compounds have recently been reported as inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase (PK), we tested our novel compounds as MRSA PK inhibitors and now report first inhibiting activities. We discuss structure-activity relationships of structurally varied compounds. Activity influencing substituents have been characterized and relations to antibacterial activities of the most active compounds have been proved.

  1. Clinical development of phosphatidylinositol-3 kinase pathway inhibitors.

    PubMed

    Arteaga, Carlos L

    2010-01-01

    The PI3K pathway is the most commonly altered in human cancer. Several recent phase I studies with therapeutic inhibitors of this pathway have shown that pharmacological inhibition of PI3K in humans is feasible and overall well tolerated. Furthermore, there has already been clinical evidence of anti-tumor activity in patients with advanced cancer. The intensity and duration of PI3K inhibition required for an antitumor effect and the optimal pharmacodynamic biomarker(s) of pathway inactivation remain to be established. Preclinical and early clinical data support focusing on trials with PI3K inhibitors that are at a minimum enriched with patients with alterations in this signaling pathway. These inhibitors are likely to be more effective in combination with established and other novel molecular therapies.

  2. A Pentacyclic Aurora Kinase Inhibitor (AKI-001) With High in Vivo Potency And Oral Bioavailability

    SciTech Connect

    Rawson, T.E.; Ruth, M.; Blackwood, E.; Burdick, D.; Corson, L.; Dotson, J.; Drummond, J.; Fields, C.; Georges, G.J.; Goller, B.; Halladay, J.; Hunsaker, T.; Kleinheinz, T.; Krell, H.-W.; Li, J.; Liang, J.; Limberg, A.; McNutt, A.; Moffat, J.; Phillips, G.; Ran, Y.

    2009-05-21

    Aurora kinase inhibitors have attracted a great deal of interest as a new class of antimitotic agents. We report a novel class of Aurora inhibitors based on a pentacyclic scaffold. A prototype pentacyclic inhibitor 32 (AKI-001) derived from two early lead structures improves upon the best properties of each parent and compares favorably to a previously reported Aurora inhibitor, 39 (VX-680). The inhibitor exhibits low nanomolar potency against both Aurora A and Aurora B enzymes, excellent cellular potency (IC{sub 50} < 100 nM), and good oral bioavailability. Phenotypic cellular assays show that both Aurora A and Aurora B are inhibited at inhibitor concentrations sufficient to block proliferation. Importantly, the cellular activity translates to potent inhibition of tumor growth in vivo. An oral dose of 5 mg/kg QD is well tolerated and results in near stasis (92% TGI) in an HCT116 mouse xenograft model.

  3. Kinase crystal identification and ATP-competitive inhibitor screening using the fluorescent ligand SKF86002.

    PubMed

    Parker, Lorien J; Taruya, Shigenao; Tsuganezawa, Keiko; Ogawa, Naoko; Mikuni, Junko; Honda, Keiko; Tomabechi, Yuri; Handa, Noriko; Shirouzu, Mikako; Yokoyama, Shigeyuki; Tanaka, Akiko

    2014-02-01

    The small kinase inhibitor SKF86002 lacks intrinsic fluorescence but becomes fluorescent upon binding to the ATP-binding sites of p38 mitogen-activated protein kinase (p38α). It was found that co-crystals of this compound with various kinases were distinguishable by their strong fluorescence. The co-crystals of SKF86002 with p38α, Pim1, ASK1, HCK and AMPK were fluorescent. Addition of SKF86002, which binds to the ATP site, to the co-crystallization solution of HCK promoted protein stability and thus facilitated the production of crystals that otherwise would not grow in the apo form. It was further demonstrated that the fluorescence of SKF86002 co-crystals can be applied to screen for candidate kinase inhibitors. When a compound binds competitively to the ATP-binding site of a kinase crystallized with SKF86002, it displaces the fluorescent SKF86002 and the crystal loses its fluorescence. Lower fluorescent signals were reported after soaking SKF86002-Pim1 and SKF86002-HCK co-crystals with the inhibitors quercetin, a quinazoline derivative and A-419259. Determination of the SKF86002-Pim1 and SKF86002-HCK co-crystal structures confirmed that SKF86002 interacts with the ATP-binding sites of Pim1 and HCK. The structures of Pim1-SKF86002 crystals soaked with the inhibitors quercetin and a quinazoline derivative and of HCK-SKF86002 crystals soaked with A-419259 were determined. These structures were virtually identical to the deposited crystal structures of the same complexes. A KINOMEscan assay revealed that SKF86002 binds a wide variety of kinases. Thus, for a broad range of kinases, SKF86002 is useful as a crystal marker, a crystal stabilizer and a marker to identify ligand co-crystals for structural analysis.

  4. Tyrosine kinase inhibitors in advanced NSCLC: A case report.

    PubMed

    Alves, Ana Ferreira; Liebermann, Marco

    2008-10-01

    Erlotinib is a molecule that selectively inhibits epidermal growth factor receptor (EGFR) tyrosine kinase activity. The authors present a case that exemplifies the use of erlotinib as second line therapy for non-small cell lung cancer (NSCLC). This case is about a 76 years old woman, non-smoker, with advanced lung adenocarcinoma (stage IIIB) previously treated with two cycles of standard chemotherapy, which were interrupted by serious adverse reactions. Rev Port Pneumol 2008; XIV (Supl 3): S23-S28.

  5. SAR and inhibitor complex structure determination of a novel class of potent and specific Aurora kinase inhibitors.

    PubMed

    Heron, Nicola M; Anderson, Malcolm; Blowers, David P; Breed, Jason; Eden, Jonathan M; Green, Stephen; Hill, George B; Johnson, Trevor; Jung, Frederic H; McMiken, Helen H J; Mortlock, Andrew A; Pannifer, Andrew D; Pauptit, Richard A; Pink, Jennifer; Roberts, Nicola J; Rowsell, Siân

    2006-03-01

    A novel series of 5-aminopyrimidinyl quinazolines has been developed from anilino-quinazoline 1, which was identified in a high throughput screen for Aurora A. Introduction of the pyrimidine ring and optimisation of the substituents both on this ring and at the C7 position of the quinazoline led to the discovery of compounds that are highly specific Aurora kinase inhibitors. Co-crystallisation of one of these inhibitors with a fragment of Aurora A shows the importance of the benzamido group in achieving selectivity.

  6. Novel pathway in Bcr-Abl signal transduction involves Akt-independent, PLC-gamma1-driven activation of mTOR/p70S6-kinase pathway.

    PubMed

    Markova, B; Albers, C; Breitenbuecher, F; Melo, J V; Brümmendorf, T H; Heidel, F; Lipka, D; Duyster, J; Huber, C; Fischer, T

    2010-02-04

    In chronic myeloid leukemia, activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway is crucial for survival and proliferation of leukemic cells. Essential downstream molecules involve mammalian target of rapamycin (mTOR) and S6-kinase. Here, we present a comprehensive analysis of the molecular events involved in activation of these key signaling pathways. We provide evidence for a previously unrecognized phospholipase C-gamma1 (PLC-gamma1)-controlled mechanism of mTOR/p70S6-kinase activation, which operates in parallel to the classical Akt-dependent machinery. Short-term imatinib treatment of Bcr-Abl-positive cells caused dephosphorylation of p70S6-K and S6-protein without inactivation of Akt. Suppression of Akt activity alone did not affect phosphorylation of p70-S6K and S6. These results suggested the existence of an alternative mechanism for mTOR/p70S6-K activation. In Bcr-Abl-expressing cells, we detected strong PLC-gamma1 activation, which was suppressed by imatinib. Pharmacological inhibition and siRNA knockdown of PLC-gamma1 blocked p70S6-K and S6 phosphorylation. By inhibiting the Ca-signaling, CaMK and PKCs we demonstrated participation of these molecules in the pathway. Suppression of PLC-gamma1 led to inhibition of cell proliferation and enhanced apoptosis. The novel pathway proved to be essential for survival and proliferation of leukemic cells and almost complete cell death was observed upon combined PLC-gamma1 and Bcr-Abl inhibition. The pivotal role of PLC-gamma1 was further confirmed in a mouse leukemogenesis model.

  7. The Tyrosine Kinase Inhibitor Sunitinib Affects Ovulation but Not Ovarian Reserve in Mouse: A Preclinical Study

    PubMed Central

    Bernard, Valérie; Bouilly, Justine; Kramer, Piet; Carré, Nadège; Schlumberger, Martin; Visser, Jenny A.; Young, Jacques; Binart, Nadine

    2016-01-01

    The aim of the study was to evaluate ovarian toxicity of tyrosine kinase inhibitor (TKI) sunitinib, since only scarce data are available on gonadal function after this treatment. Six-week-old female mice received orally, once daily, vehicle or sunitinib (50 mg/kg/d) during 5 weeks. Fertility parameters were analyzed from ovulation to litter assessment. Sunitinib exposure significantly reduced (i) corpora lutea number per ovary (1.1 ± 0.38 in sunitinib group versus 4 ± 0.79 in control group, p<0.01) and (ii) serum Anti Müllerian hormone (AMH) levels in sunitinib treated mice (12.01 ± 1.16) compared to control mice (14.33 ± 0.87 ng/ml, p< 0.05). However, primordial and growing follicles numbers per ovary were not different in both groups. After treatment withdrawal, female mice in both groups were able to obtain litters. These data could be helpful to counsel clinicians and patients, when fertility preservation methods are discussed, before TKI treatment in girls and young women. PMID:27035144

  8. Pharmacophore modeling study based on known spleen tyrosine kinase inhibitors together with virtual screening for identifying novel inhibitors.

    PubMed

    Xie, Huan-Zhang; Li, Lin-Li; Ren, Ji-Xia; Zou, Jun; Yang, Li; Wei, Yu-Quan; Yang, Sheng-Yong

    2009-04-01

    In this investigation, chemical features based 3D pharmacophore models were developed based on the known inhibitors of Spleen tyrosine kinase (Syk) with the aid of hiphop and hyporefine modules within catalyst. The best quantitative pharmacophore model, Hypo1, was used as a 3D structural query for retrieving potential inhibitors from chemical databases including Specs, NCI, MayBridge, and Chinese Nature Product Database (CNPD). The hit compounds were subsequently subjected to filtering by Lipinski's rule of five and docking studies to refine the retrieved hits. Finally 30 compounds were selected from the top ranked hit compounds and conducted an in vitro kinase inhibitory assay. Six compounds showed a good inhibitory potency against Syk, which have been selected for further investigation.

  9. Visible-Light-Triggered Activation of a Protein Kinase Inhibitor.

    PubMed

    Wilson, Danielle; Li, Jason W; Branda, Neil R

    2017-02-20

    A photoresponsive small molecule undergoes a ring-opening reaction when exposed to visible light and becomes an active inhibitor of the enzyme protein kinase C. This "turning on" of enzyme inhibition with light puts control into the hands of the user, creating the opportunity to regulate when and where enzyme catalysis takes place.

  10. Identification, SAR studies, and X-ray co-crystallographic analysis of a novel furanopyrimidine aurora kinase A inhibitor.

    PubMed

    Coumar, Mohane Selvaraj; Tsai, Ming-Tsung; Chu, Chang-Ying; Uang, Biing-Jiun; Lin, Wen-Hsing; Chang, Chun-Yu; Chang, Teng-Yuan; Leou, Jiun-Shyang; Teng, Chi-Huang; Wu, Jian-Sung; Fang, Ming-Yu; Chen, Chun-Hwa; Hsu, John T-A; Wu, Su-Ying; Chao, Yu-Sheng; Hsieh, Hsing-Pang

    2010-02-01

    Herein we reveal a simple method for the identification of novel Aurora kinase A inhibitors through substructure searching of an in-house compound library to select compounds for testing. A hydrazone fragment conferring Aurora kinase activity and heterocyclic rings most frequently reported in kinase inhibitors were used as substructure queries to filter the in-house compound library collection prior to testing. Five new series of Aurora kinase inhibitors were identified through this strategy, with IC(50) values ranging from approximately 300 nM to approximately 15 microM, by testing only 133 compounds from a database of approximately 125,000 compounds. Structure-activity relationship studies and X-ray co-crystallographic analysis of the most potent compound, a furanopyrimidine derivative with an IC(50) value of 309 nM toward Aurora kinase A, were carried out. The knowledge gained through these studies could help in the future design of potent Aurora kinase inhibitors.

  11. Loss of dendrite stabilization by the Abl-related gene (Arg) kinase regulates behavioral flexibility and sensitivity to cocaine.

    PubMed

    Gourley, Shannon L; Koleske, Anthony J; Taylor, Jane R

    2009-09-29

    Adolescence is characterized by increased vulnerability to developing neuropsychiatric disorders and involves a period of prefrontal cortical dendritic refinement and synaptic pruning that culminates in cytoskeletal stabilization in adulthood. The Abl-related gene (Arg) acts through p190RhoGAP to inhibit the RhoA GTPase and stabilize cortical dendritic arbors beginning in adolescence. Cortical axons, dendrites, and synapses develop normally in Arg-deficient (arg(-/-)) mice, but adult dendrites destabilize and regress; thus, arg(-/-) mice present a model of adolescent-onset dendritic simplification. We show that arg(-/-) mice are impaired in a reversal task and that deficits are grossly exacerbated by low-dose cocaine administration. Although ventral prefrontal dopamine D2 receptor levels predict "perseverative" error counts in wild-type mice, no such relationship is found in arg(-/-) mice. Moreover, arg(-/-) mice are insensitive to the disruptive effects of the D2/D3 antagonist haloperidol in reversal but show normal sensitivity to its locomotor-depressant actions. Arg deficiency and orbitofrontal cortical Arg inhibition via STI-571 infusion also enhance the psychomotor stimulant actions of cocaine. These findings provide evidence that stabilization of dendritic structure beginning in adolescence is critical for the development of adaptive and flexible behavior after cocaine exposure.

  12. The cardiotoxicity and myocyte damage caused by small molecule anticancer tyrosine kinase inhibitors is correlated with lack of target specificity

    SciTech Connect

    Hasinoff, Brian B.

    2010-04-15

    The use of the new anticancer tyrosine kinase inhibitors (TKI) has revolutionized the treatment of certain cancers. However, the use of some of these results in cardiotoxicity. Large-scale profiling data recently made available for the binding of 7 of the 9 FDA-approved tyrosine kinase inhibitors to a panel of 317 kinases has allowed us to correlate kinase inhibitor binding selectivity scores with TKI-induced damage to neonatal rat cardiac myocytes. The tyrosine kinase selectivity scores, but not the serine-threonine kinase scores, were highly correlated with the myocyte damaging effects of the TKIs. Additionally, we showed that damage to myocytes gave a good rank order correlation with clinical cardiotoxicity. Finally, strength of TKI binding to colony-stimulating factor 1 receptor (CSF1R) was highly correlated with myocyte damage, thus possibly implicating this kinase in contributing to TKI-induced cardiotoxicity.

  13. Tyrosine kinase inhibitors target cancer stem cells in renal cell cancer.

    PubMed

    Czarnecka, Anna M; Solarek, Wojciech; Kornakiewicz, Anna; Szczylik, Cezary

    2016-03-01

    This study was designed to analyze the impact of multi-targeted tyrosine kinase inhibitors on the cancer stem cell subpopulation in renal cell cancer. The second objective was to evaluate the effect of tumor growth inhibition related to a tumor niche factor - oxygen deprivation - as hypoxia develops along with the anti-angiogenic activity of tyrosine kinase inhibitors in renal tumors. Cells were treated with tyrosine kinase inhibitors, sunitinib, sorafenib and axitinib, in 2D and 3D culture conditions. Cell proliferation along with drug toxicity were evaluated. It was shown that the proliferation rate of cancer stem cells was decreased by the tyrosine kinase inhibitors. The efficacy of the growth inhibition was limited by hypoxic conditions and 3D intratumoral cell-cell interactions. We conclude that understanding the complex molecular interaction feedback loops between differentiated cancer cells, cancer stem cells and the tumor microenvironment in 3D culture should aid the identification of novel treatment targets and to evalute the efficacy of renal cancer therapies. Cell-cell interaction may represent a critical microenvironmental factor regulating cancer stem cell self-renewal potential, enhancing the stem cell phenotype and limiting drug toxicity. At the same time the role of hypoxia in renal cancer stem cell biology is also significant.

  14. Identification of small molecule inhibitors that block the Toxoplasma gondii rhoptry kinase ROP18.

    PubMed

    Simpson, Catherine; Jones, Nathaniel G; Hull-Ryde, Emily A; Kireev, Dmitri; Stashko, Michael; Tang, Keliang; Janetka, Jim; Wildman, Scott A; Zuercher, William J; Schapira, Matthieu; Hui, Raymond; Janzen, William; Sibley, L David

    2016-03-11

    The protozoan parasite Toxoplasma gondii secretes a family of serine-threonine protein kinases into its host cell in order to disrupt signaling and alter immune responses. One prominent secretory effector is the rhoptry protein 18 (ROP18), a serine-threonine kinase that phosphorylates immunity related GTPases (IRGs) and hence blocks interferon gamma-mediated responses in rodent cells. Previous genetic studies show that ROP18 is a major virulence component of T. gondii strains from North and South America. Here, we implemented a high throughput screen to identify small molecule inhibitors of ROP18 in vitro and subsequently validated their specificity within infected cells. Although ROP18 was not susceptible to many kinase-directed inhibitors that affect mammalian kinases, the screen identified several sub micromolar inhibitors that belong to three chemical scaffolds: oxindoles, 6-azaquinazolines, and pyrazolopyridines. Treatment of interferon gamma-activated cells with one of these inhibitors enhanced immunity related GTPase recruitment to wild type parasites, recapitulating the defect of Δrop18 mutant parasites, consistent with targeting ROP18 within infected cells. These compounds provide useful starting points for chemical biology experiments or as leads for therapeutic interventions designed to reduce parasite virulence.

  15. Tyrosine kinase inhibitor-associated syndrome of inappropriate secretion of anti-diuretic hormone.

    PubMed

    Hill, Jordan; Shields, Jenna; Passero, Vida

    2016-10-01

    Hyponatremia is a common complication among cancer patients. Certain antineoplastic agents have been associated with syndrome of inappropriate secretion of anti-diuretic hormone-induced hyponatremia. The most common agents associated with secretion of anti-diuretic hormone are vinca alkaloids, platinum compounds, and alkylating agents. We report a case of secretion of anti-diuretic hormone associated with tyrosine kinase inhibitors.

  16. Design of Targeted Inhibitors of Polo-like Kinase 1 (Plk1)

    NASA Astrophysics Data System (ADS)

    Dalafave, D. S.

    2011-03-01

    Computational design of small molecule inhibitors of Polo-like Kinase 1 (Plk1) is presented. Plk1, which regulates cell cycle, is often overexpressed in cancers. Its downregulation was shown to inhibit cancer progression. Most inhibitors of kinases' interact with the highly conserved ATP binding site. This makes the development of Plk1-specific inhibitors challenging, since different kinases have similar ATP sites. However, Plk1 also contains the polo-box domain (PBD), which is absent from other kinases. In this study, the PBD site was used as a target for designed Plk1 inhibitors. Common structural features of experimentally known Plk1 ligands were first identified. The information was used to design putative small molecules that specifically bonded Plk1. Druglikeness and possible toxicities of the designed molecules were determined. Molecules with no implied toxicities and optimal druglikeness were used for docking studies. The docking studies identified several molecules that made stable complexes with the Plk1 PBD site. Possible utilization of the designed molecules in drugs against cancers with overexpressed Plk1 is discussed.

  17. Discovery of Non-ATP-Competitive Inhibitors of Polo-like Kinase 1.

    PubMed

    Yun, Taikangxiang; Qin, Tan; Liu, Ying; Lai, Luhua

    2016-04-05

    Polo-like kinase 1 (Plk1) is an evolutionarily conserved serine/threonine kinase, and its N-terminal kinase domain (KD) controls cell signaling through phosphorylation. Inhibitors of Plk1 are potential anticancer drugs. Most known Plk1 KD inhibitors are ATP-competitive compounds, which may suffer from low selectivity. In this study we discovered novel non-ATP-competitive Plk1 KD inhibitors by virtual screening and experimental studies. Potential binding sites in Plk1 KD were identified by using the protein binding site detection program Cavity. The identified site was subjected to molecular-docking-based virtual screening. The activities of top-ranking compounds were evaluated by in vitro enzyme assay with full-length Plk1 and direct binding assay with Plk1 KD. Several compounds showed inhibitory activity, and the most potent was found to be 3-((2-oxo-2-(thiophen-2-yl)ethyl)thio)-6-(pyridin-3-ylmethyl)-1,2,4-triazin-5(4H)-one (compound 4) with an IC50 value of 13.1 ± 1.7 μm. Our work provides new insight into the design of kinase inhibitors that target non-ATP binding sites.

  18. The Adverse Effect of Hypertension in the Treatment of Thyroid Cancer with Multi-Kinase Inhibitors

    PubMed Central

    Ancker, Ole Vincent; Wehland, Markus; Bauer, Johann; Infanger, Manfred; Grimm, Daniela

    2017-01-01

    The treatment of thyroid cancer has promising prospects, mostly through the use of surgical or radioactive iodine therapy. However, some thyroid cancers, such as progressive radioactive iodine-refractory differentiated thyroid carcinoma, are not remediable with conventional types of treatment. In these cases, a treatment regimen with multi-kinase inhibitors is advisable. Unfortunately, clinical trials have shown a large number of patients, treated with multi-kinase inhibitors, being adversely affected by hypertension. This means that treatment of thyroid cancer with multi-kinase inhibitors prolongs progression-free and overall survival of patients, but a large number of patients experience hypertension as an adverse effect of the treatment. Whether the prolonged lifetime is sufficient to develop sequelae from hypertension is unclear, but late-stage cancer patients often have additional diseases, which can be complicated by the presence of hypertension. Since the exact mechanisms of the rise of hypertension in these patients are still unknown, the only available strategy is treating the symptoms. More studies determining the pathogenesis of hypertension as a side effect to cancer treatment as well as outcomes of dose management of cancer drugs are necessary to improve future therapy options for hypertension as an adverse effect to cancer therapy with multi-kinase inhibitors. PMID:28335429

  19. Novel protein kinase C inhibitors: synthesis and PKC inhibition of beta-substituted polythiophene derivatives.

    PubMed

    Xu, W C; Zhou, Q; Ashendel, C L; Chang, C T; Chang, C J

    1999-08-02

    A series of beta-substituted polythiophene derivatives was synthesized through palladium-catalyzed coupling reaction. Their structure-protein kinase C (PKC) inhibitory activity relationship was studied. The carboxaldehyde and hydroxymethyl derivatives of alpha-terthiophene were potent PKC inhibitors (IC50 = 10(-7) M).

  20. COMPARATIVE PATHOGENESIS OF HALOACETIC ACID AND PROTEIN KINASE INHIBITOR EMBRYOTOXICITY IN MOUSE WHOLE EMBRYO CULTURE

    EPA Science Inventory

    Comparative pathogenesis of haloacetic acid and protein kinase inhibitor embryotoxicity in mouse whole embryo culture.

    Ward KW, Rogers EH, Hunter ES 3rd.

    Curriculum in Toxicology, University of North Carolina at Chapel Hill, 27599-7270, USA.

    Haloacetic acids ...

  1. HALOACETIC ACIDS AND KINASE INHIBITORS PERTURB MOUSE NEURAL CREST CELLS IN VITRO

    EPA Science Inventory

    HUNTER, E.S.1, J. SMITH2, J. ANDREWS1. 1 Reproductive Toxicology Division, NHEERL, US EPA, Research Triangle Park and 2 Department of Cell and Developmental Biology, UNC-CH, Chapel Hill, North Carolina. Haloacetic acids and kinase inhibitors perturb mouse neural crest cells in vi...

  2. Arylphthalazines: identification of a new phthalazine chemotype as inhibitors of VEGFR kinase.

    PubMed

    Piatnitski, Evgueni L; Duncton, Matthew A J; Kiselyov, Alexander S; Katoch-Rouse, Reeti; Sherman, Dan; Milligan, Daniel L; Balagtas, Chris; Wong, Wai C; Kawakami, Joel; Doody, Jacqueline F

    2005-11-01

    A novel class of 4-arylamino-phthalazin-1-yl-benzamides is described as inhibitors of vascular endothelial growth factor receptor II (VEGFR-2). Several compounds display potent VEGFR-2 inhibitory activity with an IC50 as low as 0.078 microM in an HTRF enzymatic assay. These compounds are relatively selective against a small kinase panel.

  3. A High-Throughput Screen Reveals New Small-Molecule Activators and Inhibitors of Pantothenate Kinases

    PubMed Central

    2016-01-01

    Pantothenate kinase (PanK) is a regulatory enzyme that controls coenzyme A (CoA) biosynthesis. The association of PanK with neurodegeneration and diabetes suggests that chemical modifiers of PanK activity may be useful therapeutics. We performed a high throughput screen of >520000 compounds from the St. Jude compound library and identified new potent PanK inhibitors and activators with chemically tractable scaffolds. The HTS identified PanK inhibitors exemplified by the detailed characterization of a tricyclic compound (7) and a preliminary SAR. Biophysical studies reveal that the PanK inhibitor acts by binding to the ATP–enzyme complex. PMID:25569308

  4. Assay for isolation of inhibitors of her2-kinase expression.

    PubMed

    Chiosis, Gabriela; Keeton, Adam B

    2009-01-01

    Her2 (ErbB2) protein is overexpressed in breast and other solid tumors, and its expression is associated with progressive disease. Current therapies directed toward Her2 either block dimerization of the receptor or inhibit tyrosine kinase activity to disrupt intracellular signaling. However, little is known about alternative mechanisms for suppressing Her2 expression, possibly by inducing degradation or blocking synthesis. Here, we describe a hybrid western-blotting and enzyme-linked immunosorbent assay (ELISA) designed to identify in low- to medium-throughput format noncytotoxic compounds that reduce expression of Her2 protein.

  5. Risk of Infectious Complications in Hemato-Oncological Patients Treated with Kinase Inhibitors

    PubMed Central

    Reinwald, Mark; Boch, Tobias; Hofmann, Wolf-Karsten; Buchheidt, Dieter

    2015-01-01

    Infectious complications are a major cause of morbidity and mortality in patients with hemato-oncological diseases. Although disease-related immunosuppression represents one factor, aggressive treatment regimens, such as chemotherapy, stem cell transplantation, or antibody treatment, account for a large proportion of infectious side effects. With the advent of targeted therapies affecting specific kinases in malignant diseases, the outcome of patients has further improved. Nonetheless, dependent on the specific pathway targeted or off-target activity of the kinase inhibitor, therapy-associated infectious complications may occur. We review the most common and approved kinase inhibitors targeting a variety of hemato-oncological malignancies for their immunosuppressive potential and evaluate their risk of infectious side effects based on preclinical evidence and clinical data in order to raise awareness of the potential risks involved. PMID:27127405

  6. Discovery of a Selective Inhibitor of Oncogenic B-Raf Kinase With Potent Antimelanoma Activity

    SciTech Connect

    Tsai, J.; Lee, J.T.; Wang, W.; Zhang, J.; Cho, H.; Mamo, S.; Bremer, R.; Gillette, S.; Kong, J.; Haass, N.K.; Sproesser, K.; Li, L.; Smalley, K.S.M.; Fong, D.; Zhu, Y.-L.; Marimuthu, A.; Nguyen, H.; Lam, B.; Liu, J.; Cheung, I.; Rice, J.

    2009-05-26

    BRAF{sup V600E} is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting 'active' protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-Raf{sup V600E} with an IC{sub 50} of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4720 preferentially inhibits the active B-Raf{sup V600E} kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-Raf{sup V600E}-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-Raf{sup V600E}-positive cells. In B-Raf{sup V600E}-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-Raf{sup V600E}-driven tumors.

  7. A Novel Triazolopyridine-Based Spleen Tyrosine Kinase Inhibitor That Arrests Joint Inflammation

    PubMed Central

    Ferguson, Gregory D.; Delgado, Mercedes; Plantevin-Krenitsky, Veronique; Jensen-Pergakes, Kristen; Bates, R. J.; Torres, Sanaa; Celeridad, Maria; Brown, Heather; Burnett, Kelven; Nadolny, Lisa; Tehrani, Lida; Packard, Garrick; Pagarigan, Barbra; Haelewyn, Jason; Nguyen, Trish; Xu, Li; Tang, Yang; Hickman, Matthew; Baculi, Frans; Pierce, Steven; Miyazawa, Keiji; Jackson, Pilgrim; Chamberlain, Philip; LeBrun, Laurie; Xie, Weilin; Bennett, Brydon; Blease, Kate

    2016-01-01

    Autoantibodies and the immunoreceptors to which they bind can contribute to the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA). Spleen Tyrosine Kinase (Syk) is a non-receptor tyrosine kinase with a central role in immunoreceptor (FcR) signaling and immune cell functionality. Syk kinase inhibitors have activity in antibody-dependent immune cell activation assays, in preclinical models of arthritis, and have progressed into clinical trials for RA and other autoimmune diseases. Here we describe the characterization of a novel triazolopyridine-based Syk kinase inhibitor, CC-509. This compound is a potent inhibitor of purified Syk enzyme, FcR-dependent and FcR-independent signaling in primary immune cells, and basophil activation in human whole blood. CC-509 is moderately selective across the kinome and against other non-kinase enzymes or receptors. Importantly, CC-509 was optimized away from and has modest activity against cellular KDR and Jak2, kinases that when inhibited in a preclinical and clinical setting may promote hypertension and neutropenia, respectively. In addition, CC-509 is orally bioavailable and displays dose-dependent efficacy in two rodent models of immune-inflammatory disease. In passive cutaneous anaphylaxis (PCA), CC-509 significantly inhibited skin edema. Moreover, CC-509 significantly reduced paw swelling and the tissue levels of pro-inflammatory cytokines RANTES and MIP-1α in the collagen-induced arthritis (CIA) model. In summary, CC-509 is a potent, moderately selective, and efficacious inhibitor of Syk that has a differentiated profile when compared to other Syk compounds that have progressed into the clinic for RA. PMID:26756335

  8. A Novel Triazolopyridine-Based Spleen Tyrosine Kinase Inhibitor That Arrests Joint Inflammation.

    PubMed

    Ferguson, Gregory D; Delgado, Mercedes; Plantevin-Krenitsky, Veronique; Jensen-Pergakes, Kristen; Bates, R J; Torres, Sanaa; Celeridad, Maria; Brown, Heather; Burnett, Kelven; Nadolny, Lisa; Tehrani, Lida; Packard, Garrick; Pagarigan, Barbra; Haelewyn, Jason; Nguyen, Trish; Xu, Li; Tang, Yang; Hickman, Matthew; Baculi, Frans; Pierce, Steven; Miyazawa, Keiji; Jackson, Pilgrim; Chamberlain, Philip; LeBrun, Laurie; Xie, Weilin; Bennett, Brydon; Blease, Kate

    2016-01-01

    Autoantibodies and the immunoreceptors to which they bind can contribute to the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA). Spleen Tyrosine Kinase (Syk) is a non-receptor tyrosine kinase with a central role in immunoreceptor (FcR) signaling and immune cell functionality. Syk kinase inhibitors have activity in antibody-dependent immune cell activation assays, in preclinical models of arthritis, and have progressed into clinical trials for RA and other autoimmune diseases. Here we describe the characterization of a novel triazolopyridine-based Syk kinase inhibitor, CC-509. This compound is a potent inhibitor of purified Syk enzyme, FcR-dependent and FcR-independent signaling in primary immune cells, and basophil activation in human whole blood. CC-509 is moderately selective across the kinome and against other non-kinase enzymes or receptors. Importantly, CC-509 was optimized away from and has modest activity against cellular KDR and Jak2, kinases that when inhibited in a preclinical and clinical setting may promote hypertension and neutropenia, respectively. In addition, CC-509 is orally bioavailable and displays dose-dependent efficacy in two rodent models of immune-inflammatory disease. In passive cutaneous anaphylaxis (PCA), CC-509 significantly inhibited skin edema. Moreover, CC-509 significantly reduced paw swelling and the tissue levels of pro-inflammatory cytokines RANTES and MIP-1α in the collagen-induced arthritis (CIA) model. In summary, CC-509 is a potent, moderately selective, and efficacious inhibitor of Syk that has a differentiated profile when compared to other Syk compounds that have progressed into the clinic for RA.

  9. A Small-Molecule Inhibitor of PIM Kinases as a Potential Treatment for Urothelial Carcinomas12

    PubMed Central

    Foulks, Jason M.; Carpenter, Kent J.; Luo, Bai; Xu, Yong; Senina, Anna; Nix, Rebecca; Chan, Ashley; Clifford, Adrianne; Wilkes, Marcus; Vollmer, David; Brenning, Benjamin; Merx, Shannon; Lai, Shuping; McCullar, Michael V.; Ho, Koc-Kan; Albertson, Daniel J.; Call, Lee T.; Bearss, Jared J.; Tripp, Sheryl; Liu, Ting; Stephens, Bret J.; Mollard, Alexis; Warner, Steven L.; Bearss, David J.; Kanner, Steven B.

    2014-01-01

    The proto-oncogene proviral integration site for moloney murine leukemia virus (PIM) kinases (PIM-1, PIM-2, and PIM-3) are serine/threonine kinases that are involved in a number of signaling pathways important to cancer cells. PIM kinases act in downstream effector functions as inhibitors of apoptosis and as positive regulators of G1-S phase progression through the cell cycle. PIM kinases are upregulated in multiple cancer indications, including lymphoma, leukemia, multiple myeloma, and prostate, gastric, and head and neck cancers. Overexpression of one or more PIM family members in patient tumors frequently correlates with poor prognosis. The aim of this investigation was to evaluate PIM expression in low- and high-grade urothelial carcinoma and to assess the role PIM function in disease progression and their potential to serve as molecular targets for therapy. One hundred thirty-seven cases of urothelial carcinoma were included in this study of surgical biopsy and resection specimens. High levels of expression of all three PIM family members were observed in both noninvasive and invasive urothelial carcinomas. The second-generation PIM inhibitor, TP-3654, displays submicromolar activity in pharmacodynamic biomarker modulation, cell proliferation studies, and colony formation assays using the UM-UC-3 bladder cancer cell line. TP-3654 displays favorable human ether-à-go-go-related gene and cytochrome P450 inhibition profiles compared with the first-generation PIM inhibitor, SGI-1776, and exhibits oral bioavailability. In vivo xenograft studies using a bladder cancer cell line show that PIM kinase inhibition can reduce tumor growth, suggesting that PIM kinase inhibitors may be active in human urothelial carcinomas. PMID:24953177

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Effects of BP-14, a novel cyclin-dependent kinase inhibitor, on anaplastic thyroid cancer cells.

    PubMed

    Allegri, Lorenzo; Baldan, Federica; Mio, Catia; Puppin, Cinzia; Russo, Diego; Kryštof, Vladimir; Damante, Giuseppe

    2016-04-01

    Anaplastic thyroid carcinoma (ATC) is an extremely aggressive human malignancy characterized by a marked degree of invasiveness, absense of features of thyroid differentiation and resistance to current medical treatment. It is well known that ATCs are characterized by deregulation of genes related to cell cycle regulation, i.e., cyclin-dependent kinases (CDKs) and endogenous cyclin-dependent kinase inhibitors (CDKIs). Therefore, in the present study, the effect of a novel exogenous cyclin-dependent kinase inhibitor, BP-14, was investigated in three human ATC cell lines. The ATC-derived cell lines FRO, SW1736 and 8505C were treated with BP-14 alone or in combination with the mTOR inhibitor everolimus. In all ATC cell lines, treatment with BP-14 decreased cell viability and, in two of them, BP-14 modified expression of genes involved in epithelial-mesenchymal transition. Thus, our data indicate that BP-14 is a potential new compound effective against ATC. Combined treatment with BP-14 and the mTOR inhibitor everolimus had a strong synergistic effect on cell viability in all three cell lines, suggesting that the combined used of CDK and mTOR inhibitors may be a useful strategy for ATC treatment.

  12. Identification of Polo-like kinase 1 interaction inhibitors using a novel cell-based assay

    PubMed Central

    Normandin, Karine; Lavallée, Jean-François; Futter, Marie; Beautrait, Alexandre; Duchaine, Jean; Guiral, Sébastien; Marinier, Anne; Archambault, Vincent

    2016-01-01

    Polo-like kinase 1 (Plk1) plays several roles in cell division and it is a recognized cancer drug target. Plk1 levels are elevated in cancer and several types of cancer cells are hypersensitive to Plk1 inhibition. Small molecule inhibitors of the kinase domain (KD) of Plk1 have been developed. Their selectivity is limited, which likely contributes to their toxicity. Polo-like kinases are characterized by a Polo-Box Domain (PBD), which mediates interactions with phosphorylation substrates or regulators. Inhibition of the PBD could allow better selectivity or result in different effects than inhibition of the KD. In vitro screens have been used to identify PBD inhibitors with mixed results. We developed the first cell-based assay to screen for PBD inhibitors, using Bioluminescence Resonance Energy Transfer (BRET). We screened through 112 983 compounds and characterized hits in secondary biochemical and biological assays. Subsequent Structure-Activity Relationship (SAR) analysis on our most promising hit revealed that it requires an alkylating function for its activity. In addition, we show that the previously reported PBD inhibitors thymoquinone and Poloxin are also alkylating agents. Our cell-based assay is a promising tool for the identification of new PBD inhibitors with more drug-like profiles using larger and more diverse chemical libraries. PMID:27874094

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

    SciTech Connect

    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.

  14. Key Structures and Interactions for Binding of Mycobacterium tuberculosis Protein Kinase B Inhibitors from Molecular Dynamics Simulation.

    PubMed

    Punkvang, Auradee; Kamsri, Pharit; Saparpakorn, Patchreenart; Hannongbua, Supa; Wolschann, Peter; Irle, Stephan; Pungpo, Pornpan

    2015-07-01

    Substituted aminopyrimidine inhibitors have recently been introduced as antituberculosis agents. These inhibitors show impressive activity against protein kinase B, a Ser/Thr protein kinase that is essential for cell growth of M. tuberculosis. However, up to now, X-ray structures of the protein kinase B enzyme complexes with the substituted aminopyrimidine inhibitors are currently unavailable. Consequently, structural details of their binding modes are questionable, prohibiting the structural-based design of more potent protein kinase B inhibitors in the future. Here, molecular dynamics simulations, in conjunction with molecular mechanics/Poisson-Boltzmann surface area binding free-energy analysis, were employed to gain insight into the complex structures of the protein kinase B inhibitors and their binding energetics. The complex structures obtained by the molecular dynamics simulations show binding free energies in good agreement with experiment. The detailed analysis of molecular dynamics results shows that Glu93, Val95, and Leu17 are key residues responsible to the binding of the protein kinase B inhibitors. The aminopyrazole group and the pyrimidine core are the crucial moieties of substituted aminopyrimidine inhibitors for interaction with the key residues. Our results provide a structural concept that can be used as a guide for the future design of protein kinase B inhibitors with highly increased antagonistic activity.

  15. Small tyrosine kinase inhibitors interrupt EGFR signaling by interacting with erbB3 and erbB4 in glioblastoma cell lines

    SciTech Connect

    Carrasco-Garcia, Estefania; Saceda, Miguel; Grasso, Silvina; Rocamora-Reverte, Lourdes; Conde, Mariano; Gomez-Martinez, Angeles; Garcia-Morales, Pilar; Ferragut, Jose A.; Martinez-Lacaci, Isabel

    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.

  16. Development of a cell-based, high-throughput screening assay for ATM kinase inhibitors.

    PubMed

    Guo, Kexiao; Shelat, Anang A; Guy, R Kiplin; Kastan, Michael B

    2014-04-01

    The ATM (ataxia-telangiectasia, mutated) protein kinase is a major regulator of cellular responses to DNA double-strand breaks (DSBs), DNA lesions that can be caused by ionizing irradiation (IR), oxidative damage, or exposure to certain chemical agents. In response to DSBs, the ATM kinase is activated and subsequently phosphorylates numerous downstream substrates, including p53, Chk2, BRCA1, and KAP1, which affect processes such as cell cycle progression and DNA repair. Numerous studies have demonstrated that loss of ATM function results in enhanced sensitivity to ionizing irradiation in clinically relevant dose ranges, suggesting that ATM kinase is an attractive therapeutic target for enhancing tumor cell kill with radiotherapy. Previously identified small-molecule ATM kinase inhibitors, such as CP466722 and Ku55933, were identified using in vitro kinase assays carried out with recombinant ATM kinase isolated from mammalian cells. Since it has not been feasible to express full-length recombinant ATM in bacterial or baculovirus systems, a robust in vitro screening tool has been lacking. We have developed a cell-based assay that is robust, straightforward, and sensitive. Using this high-throughput assay, we screened more than 7000 compounds and discovered additional small molecules that inhibit the ATM kinase and further validated these hits by secondary assays.

  17. Novel irreversible EGFR tyrosine kinase inhibitor 324674 sensitizes human colon carcinoma HT29 and SW480 cells to apoptosis by blocking the EGFR pathway

    SciTech Connect

    Yu, Zhiwei; Cui, Binbin; Jin, Yinghu; Chen, Haipeng; Wang, Xishan

    2011-08-12

    Highlights: {yields} This article described the effects of the EGFR tyrosine kinase inhibitor on the cell proliferation and the apoptosis induction of the colon carcinoma cell lines. {yields} Demonstrated that 326474 is a more potent EGFR inhibitor on colon cancer cells than other three TKIs. {yields} It can be important when considering chemotherapy for colonic cancer patients. -- Abstract: Background: Epidermal growth factor receptor (EGFR) is widely expressed in multiple solid tumors including colorectal cancer by promoting cancer cell growth and proliferation. Therefore, the inhibition of EGFR activity may establish a clinical strategy of cancer therapy. Methods: In this study, using human colon adenocarcinoma HT29 and SW480 cells as research models, we compared the efficacy of four EGFR inhibitors in of EGFR-mediated pathways, including the novel irreversible inhibitor 324674, conventional reversible inhibitor AG1478, dual EGFR/HER2 inhibitor GW583340 and the pan-EGFR/ErbB2/ErbB4 inhibitor. Cell proliferation was assessed by MTT analysis, and apoptosis was evaluated by the Annexin-V binding assay. EGFR and its downstream signaling effectors were examined by western blotting analysis. Results: Among the four inhibitors, the irreversible EGFR inhibitor 324674 was more potent at inhibiting HT29 and SW480 cell proliferation and was able to efficiently induce apoptosis at lower concentrations. Western blotting analysis revealed that AG1478, GW583340 and pan-EGFR/ErbB2/ErbB4 inhibitors failed to suppress EGFR activation as well as the downstream mitogen-activated protein kinase (MAPK) and PI3K/AKT/mTOR (AKT) pathways. In contrast, 324674 inhibited EGFR activation and the downstream AKT signaling pathway in a dose-dependent manner. Conclusion: Our studies indicated that the novel irreversible EGFR inhibitor 324674 may have a therapeutic application in colon cancer therapy.

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

    SciTech Connect

    Homan, Kristoff T.; Larimore, Kelly M.; Elkins, Jonathan M.; Szklarz, Marta; Knapp, Stefan; Tesmer, John J.G.

    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.

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

    PubMed Central

    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. PMID:24989836

  20. Divergent allosteric control of the IRE1α endoribonuclease using kinase inhibitors

    PubMed Central

    Wang, Likun; Perera, B. Gayani K.; Hari, Sanjay B.; Bhhatarai, Barun; Backes, Bradley J.; Seeliger, Markus A.; Schürer, Stephan C.; Oakes, Scott A.; Papa, Feroz R.; Maly, Dustin J.

    2012-01-01

    Under endoplasmic reticulum (ER) stress, unfolded proteins accumulate in the ER to activate the ER transmembrane kinase/endoribonuclease (RNase)—IRE1α. IRE1α oligomerizes, autophosphorylates, and initiates splicing of XBP1 mRNA, thus triggering the unfolded protein response (UPR). Here we show that IRE1α’s kinase-controlled RNase can be regulated in two distinct modes with kinase inhibitors: one class of ligands occupy IRE1α’s kinase ATP-binding site to activate RNase-mediated XBP1 mRNA splicing even without upstream ER stress, while a second class can inhibit the RNase through the same ATP-binding site, even under ER stress. Thus, alternative kinase conformations stabilized by distinct classes of ATP-competitive inhibitors can cause allosteric switching of IRE1α’s RNase—either on or off. As dysregulation of the UPR has been implicated in a variety of cell degenerative and neoplastic disorders, small molecule control over IRE1α should advance efforts to understand the UPR’s role in pathophysiology and to develop drugs for ER stress-related diseases. PMID:23086298

  1. The kinase ABL phosphorylates the microprocessor subunit DGCR8 to stimulate primary microRNA processing in response to DNA damage.

    PubMed

    Tu, Chi-Chiang; Zhong, Yan; Nguyen, Louis; Tsai, Aaron; Sridevi, Priya; Tarn, Woan-Yuh; Wang, Jean Y J

    2015-06-30

    The DNA damage response network stimulates microRNA (miRNA) biogenesis to coordinate repair, cell cycle checkpoints, and apoptosis. The multistep process of miRNA biogenesis involves the cleavage of primary miRNAs by the microprocessor complex composed of the ribonuclease Drosha and the RNA binding protein DGCR8. We found that the tyrosine kinase ABL phosphorylated DGCR8, a modification that was required for the induction of a subset of miRNAs after DNA damage. Focusing on the miR-34 family, ABL stimulated the production of miR-34c, but not miR-34a, through Drosha/DGCR8-dependent processing of primary miR-34c (pri-miR-34c). This miRNA-selective effect of ABL required the sequences flanking the precursor miR-34c (pre-miR-34c) stem-loop. In pri-miRNA processing, DGCR8 binds the pre-miR stem-loop and recruits Drosha to the miRNA. RNA cross-linking assays showed that DGCR8 and Drosha interacted with pri-miR-34c, but we found an inverse correlation between ABL-stimulated processing and DGCR8 association with pri-miR-34c. When coexpressed in HEK293T cells, ABL phosphorylated DGCR8 at Tyr(267). Ectopic expression of a Y267F-DGCR8 mutant reduced the recruitment of Drosha to pri-miR-34c and prevented ABL or Drosha from stimulating the processing of pri-miR-34c. In mice engineered to express a nuclear import-defective mutant of ABL, miR-34c, but not miR-34a, expression was reduced in the kidney, and apoptosis of the renal epithelial cells was impaired in response to cisplatin. These results reveal a new pathway in the DNA damage response wherein ABL-dependent tyrosine phosphorylation of DGCR8 stimulates the processing of selective primary miRNAs.

  2. A Small Molecule Bidentate-Binding Dual Inhibitor Probe of the LRRK2 and JNK Kinases

    PubMed Central

    Feng, Yangbo; Chambers, Jeremy W.; Iqbal, Sarah; Koenig, Marcel; Park, HaJeung; Cherry, Lisa; Hernandez, Pamela; Figuera-Losada, Mariana; LoGrasso, Philip V.

    2013-01-01

    Both JNK and LRRK2 are associated with Parkinson’s disease (PD). Here we report a reasonably selective and potent kinase inhibitor (compound 6) that bound to both JNK and LRRK2 (a dual inhibitor). A bidentate-binding strategy that simultaneously utilized the ATP hinge binding and a unique protein surface site outside of the ATP pocket was applied to the design and identification of this kind of inhibitor. Compound 6 was a potent JNK3 and modest LRRK2 dual inhibitor with an enzyme IC50 value of 12 nM and 99 nM (LRRK2-G2019S), respectively. 6 also exhibited good cell potency, inhibited LRRK2:G2019S induced mitochondrial dysfunction in SHSY5Y cells, and was demonstrated to be reasonably selective against a panel of 116 kinases from representative kinase families. Design of such a probe molecule may help enable testing if dual JNK and LRRK2 inhibitions have added or synergistic efficacy in protecting against neurodegeneration in PD. PMID:23751758

  3. QSAR and molecular docking studies on oxindole derivatives as VEGFR-2 tyrosine kinase inhibitors.

    PubMed

    Kang, Cong-Min; Liu, Dong-Qing; Zhao, Xu-Hao; Dai, Ying-Jie; Cheng, Jia-Gao; Lv, Ying-Tao

    2016-01-01

    The three-dimensional quantitative structure-activity relationships (3D-QSAR) were established for 30 oxindole derivatives as vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase inhibitors by using comparative molecular field analysis (CoMFA) and comparative similarity indices analysis comparative molecular similarity indices analysis (CoMSIA) techniques. With the CoMFA model, the cross-validated value (q(2)) was 0.777, the non-cross-validated value (R(2)) was 0.987, and the external cross-validated value ([Formula: see text]) was 0.72. And with the CoMSIA model, the corresponding q(2), R(2) and [Formula: see text] values were 0.710, 0.988 and 0.78, respectively. Docking studies were employed to bind the inhibitors into the active site to determine the probable binding conformation. The binding mode obtained by molecular docking was in good agreement with the 3D-QSAR results. Based on the QSAR models and the docking binding mode, a set of new VEGFR-2 tyrosine kinase inhibitors were designed, which showed excellent predicting inhibiting potencies. The result revealed that both QSAR models have good predictive capability to guide the design and structural modification of homologic compounds. It is also helpful for further research and development of new VEGFR-2 tyrosine kinase inhibitors.

  4. Cables links Robo-bound Abl kinase to N-cadherin-bound beta-catenin to mediate Slit-induced modulation of adhesion and transcription.

    PubMed

    Rhee, Jinseol; Buchan, Tim; Zukerberg, Lawrence; Lilien, Jack; Balsamo, Janne

    2007-08-01

    Binding of the secreted axon guidance cue Slit to its Robo receptor results in inactivation of the neural, calcium-dependent cell-cell adhesion molecule N-cadherin, providing a rapid epigenetic mechanism for integrating guidance and adhesion information. This requires the formation of a multimolecular complex containing Robo, Abl tyrosine kinase and N-cadherin. Here we show that on binding of Slit to Robo, the adaptor protein Cables is recruited to Robo-associated Abl and forms a multimeric complex by binding directly to N-cadherin-associated beta-catenin. Complex formation results in Abl-mediated phosphorylation of beta-catenin on tyrosine 489, leading to a decrease in its affinity for N-cadherin, loss of N-cadherin function, and targeting of phospho-Y489-beta-catenin to the nucleus. Nuclear beta-catenin combines with the transcription factor Tcf/Lef and activates transcription. Thus, Slit-induced formation of the Robo-N-cadherin complex results in a rapid loss of cadherin-mediated adhesion and has more lasting effects on gene transcription.

  5. Discovery of Pyrrolopyridine−Pyridone Based Inhibitors of Met Kinase: Synthesis, X-ray Crystallographic Analysis, and Biological Activities

    SciTech Connect

    Kim, Kyoung Soon; Zhang, Liping; Schmidt, Robert; Cai, Zhen-Wei; Wei, Donna; Williams, David K.; Lombardo, Louis J.; Trainor, George L.; Xie, Dianlin; Zhang, Yaquan; An, Yongmi; Sack, John S.; Tokarski, John S.; Darienzo, Celia; Kamath, Amrita; Marathe, Punit; Zhang, Yueping; Lippy, Jonathan; Jeyaseelan, Sr., Robert; Wautlet, Barri; Henley, Benjamin; Gullo-Brown, Johnni; Manne, Veeraswamy; Hunt, John T.; Fargnoli, Joseph; Borzilleri, Robert M.

    2008-10-02

    Conformationally constrained 2-pyridone analogue 2 is a potent Met kinase inhibitor with an IC50 value of 1.8 nM. Further SAR of the 2-pyridone based inhibitors of Met kinase led to potent 4-pyridone and pyridine N-oxide inhibitors such as 3 and 4. The X-ray crystallographic data of the inhibitor 2 bound to the ATP binding site of Met kinase protein provided insight into the binding modes of these inhibitors, and the SAR of this series of analogues was rationalized. Many of these analogues showed potent antiproliferative activities against the Met dependent GTL-16 gastric carcinoma cell line. Compound 2 also inhibited Flt-3 and VEGFR-2 kinases with IC{sub 50} values of 4 and 27 nM, respectively. It possesses a favorable pharmacokinetic profile in mice and demonstrates significant in vivo antitumor activity in the GTL-16 human gastric carcinoma xenograft model.

  6. A class of selective antibacterials derived from a protein kinase inhibitor pharmacophore.

    PubMed

    Miller, J Richard; Dunham, Steve; Mochalkin, Igor; Banotai, Craig; Bowman, Matthew; Buist, Susan; Dunkle, Bill; Hanna, Debra; Harwood, H James; Huband, Michael D; Karnovsky, Alla; Kuhn, Michael; Limberakis, Chris; Liu, Jia Y; Mehrens, Shawn; Mueller, W Thomas; Narasimhan, Lakshmi; Ogden, Adam; Ohren, Jeff; Prasad, J V N Vara; Shelly, John A; Skerlos, Laura; Sulavik, Mark; Thomas, V Hayden; VanderRoest, Steve; Wang, LiAnn; Wang, Zhigang; Whitton, Amy; Zhu, Tong; Stover, C Kendall

    2009-02-10

    As the need for novel antibiotic classes to combat bacterial drug resistance increases, the paucity of leads resulting from target-based antibacterial screening of pharmaceutical compound libraries is of major concern. One explanation for this lack of success is that antibacterial screening efforts have not leveraged the eukaryotic bias resulting from more extensive chemistry efforts targeting eukaryotic gene families such as G protein-coupled receptors and protein kinases. Consistent with a focus on antibacterial target space resembling these eukaryotic targets, we used whole-cell screening to identify a series of antibacterial pyridopyrimidines derived from a protein kinase inhibitor pharmacophore. In bacteria, the pyridopyrimidines target the ATP-binding site of biotin carboxylase (BC), which catalyzes the first enzymatic step of fatty acid biosynthesis. These inhibitors are effective in vitro and in vivo against fastidious gram-negative pathogens including Haemophilus influenzae. Although the BC active site has architectural similarity to those of eukaryotic protein kinases, inhibitor binding to the BC ATP-binding site is distinct from the protein kinase-binding mode, such that the inhibitors are selective for bacterial BC. In summary, we have discovered a promising class of potent antibacterials with a previously undescribed mechanism of action. In consideration of the eukaryotic bias of pharmaceutical libraries, our findings also suggest that pursuit of a novel inhibitor leads for antibacterial targets with active-site structural similarity to known human targets will likely be more fruitful than the traditional focus on unique bacterial target space, particularly when structure-based and computational methodologies are applied to ensure bacterial selectivity.

  7. Effects of selective inhibitors of Aurora kinases on anaplastic thyroid carcinoma cell lines.

    PubMed

    Baldini, Enke; Tuccilli, Chiara; Prinzi, Natalie; Sorrenti, Salvatore; Antonelli, Alessandro; Gnessi, Lucio; Morrone, Stefania; Moretti, Costanzo; Bononi, Marco; Arlot-Bonnemains, Yannick; D'Armiento, Massimino; Ulisse, Salvatore

    2014-10-01

    Aurora kinases are serine/threonine kinases that play an essential role in cell division. Their aberrant expression and/or function induce severe mitotic abnormalities, resulting in either cell death or aneuploidy. Overexpression of Aurora kinases is often found in several malignancies, among which is anaplastic thyroid carcinoma (ATC). We have previously demonstrated the in vitro efficacy of Aurora kinase inhibitors in restraining cell growth and survival of different ATC cell lines. In this study, we sought to establish which Aurora might represent the preferential drug target for ATC. To this end, the effects of two selective inhibitors of Aurora-A (MLN8237) and Aurora-B (AZD1152) on four human ATC cell lines (CAL-62, BHT-101, 8305C, and 8505C) were analysed. Both inhibitors reduced cell proliferation in a time- and dose-dependent manner, with IC50 ranges of 44.3-134.2 nM for MLN8237 and of 9.2-461.3 nM for AZD1152. Immunofluorescence experiments and time-lapse videomicroscopy yielded evidence that each inhibitor induced distinct mitotic phenotypes, but both of them prevented the completion of cytokinesis. As a result, poliploidy increased in all AZD1152-treated cells, and in two out of four cell lines treated with MLN8237. Apoptosis was induced in all the cells by MLN8237, and in BHT-101, 8305C, and 8505C by AZD1152, while CAL-62 exposed to AZD1152 died through necrosis after multiple rounds of endoreplication. Both inhibitors were capable of blocking anchorage-independent cell growth. In conclusion, we demonstrated that either Aurora-A or Aurora-B might represent therapeutic targets for the ATC treatment, but inhibition of Aurora-A appears more effective for suppressing ATC cell proliferation and for inducing the apoptotic pathway.

  8. A class of selective antibacterials derived from a protein kinase inhibitor pharmacophore

    SciTech Connect

    Miller, J. Richard; Dunham, Steve; Mochalkin, Igor; Banotai, Craig; Bowman, Matthew; Buist, Susan; Dunkle, Bill; Hanna, Debra; Harwood, H. James; Huband, Michael D.; Karnovsky, Alla; Kuhn, Michael; Limberakis, Chris; Liu, Jia Y.; Mehrens, Shawn; Mueller, W. Thomas; Narasimhan, Lakshmi; Ogden, Adam; Ohren, Jeff; Prasad, J.V.N. Vara; Shelly, John A.; Skerlos, Laura; Sulavik, Mark; Thomas, V. Hayden; VanderRoest, Steve; Wang, LiAnn; Wang, Zhigang; Whitton, Amy; Zhu, Tong; Stover, C. Kendall

    2009-06-25

    As the need for novel antibiotic classes to combat bacterial drug resistance increases, the paucity of leads resulting from target-based antibacterial screening of pharmaceutical compound libraries is of major concern. One explanation for this lack of success is that antibacterial screening efforts have not leveraged the eukaryotic bias resulting from more extensive chemistry efforts targeting eukaryotic gene families such as G protein-coupled receptors and protein kinases. Consistent with a focus on antibacterial target space resembling these eukaryotic targets, we used whole-cell screening to identify a series of antibacterial pyridopyrimidines derived from a protein kinase inhibitor pharmacophore. In bacteria, the pyridopyrimidines target the ATP-binding site of biotin carboxylase (BC), which catalyzes the first enzymatic step of fatty acid biosynthesis. These inhibitors are effective in vitro and in vivo against fastidious Gram-negative pathogens including Haemophilus influenzae. Although the BC active site has architectural similarity to those of eukaryotic protein kinases, inhibitor binding to the BC ATP-binding site is distinct from the protein kinase-binding mode, such that the inhibitors are selective for bacterial BC. In summary, we have discovered a promising class of potent antibacterials with a previously undescribed mechanism of action. In consideration of the eukaryotic bias of pharmaceutical libraries, our findings also suggest that pursuit of a novel inhibitor leads for antibacterial targets with active-site structural similarity to known human targets will likely be more fruitful than the traditional focus on unique bacterial target space, particularly when structure-based and computational methodologies are applied to ensure bacterial selectivity.

  9. Discovery of Small Molecule RIP1 Kinase Inhibitors for the Treatment of Pathologies Associated with Necroptosis

    PubMed Central

    2013-01-01

    Potent inhibitors of RIP1 kinase from three distinct series, 1-aminoisoquinolines, pyrrolo[2,3-b]pyridines, and furo[2,3-d]pyrimidines, all of the type II class recognizing a DLG-out inactive conformation, were identified from screening of our in-house kinase focused sets. An exemplar from the furo[2,3-d]pyrimidine series showed a dose proportional response in protection from hypothermia in a mouse model of TNFα induced lethal shock. PMID:24900635

  10. Using ovality to predict nonmutagenic, orally efficacious pyridazine amides as cell specific spleen tyrosine kinase inhibitors.

    PubMed

    Lucas, Matthew C; Bhagirath, Niala; Chiao, Eric; Goldstein, David M; Hermann, Johannes C; Hsu, Pei-Yuan; Kirchner, Stephan; Kennedy-Smith, Joshua J; Kuglstatter, Andreas; Lukacs, Christine; Menke, John; Niu, Linghao; Padilla, Fernando; Peng, Ying; Polonchuk, Liudmila; Railkar, Aruna; Slade, Michelle; Soth, Michael; Xu, Daigen; Yadava, Preeti; Yee, Calvin; Zhou, Mingyan; Liao, Cheng

    2014-03-27

    Inhibition of spleen tyrosine kinase has attracted much attention as a mechanism for the treatment of cancers and autoimmune diseases such as asthma, rheumatoid arthritis, and systemic lupus erythematous. We report the structure-guided optimization of pyridazine amide spleen tyrosine kinase inhibitors. Early representatives of this scaffold were highly potent and selective but mutagenic in an Ames assay. An approach that led to the successful identification of nonmutagenic examples, as well as further optimization to compounds with reduced cardiovascular liabilities is described. Select pharmacokinetic and in vivo efficacy data are presented.

  11. An interaction map of small-molecule kinase inhibitors with anaplastic lymphoma kinase (ALK) mutants in ALK-positive non-small cell lung cancer.

    PubMed

    Ai, Xinghao; Shen, Shengping; Shen, Lan; Lu, Shun

    2015-05-01

    Human anaplastic lymphoma kinase (ALK) has become a well-established target for the treatment of ALK-positive non-small cell lung cancer (NSCLC). Here, we have profiled seven small-molecule inhibitors, including 2 that are approved drugs, against a panel of clinically relevant mutations in ALK tyrosine kinase (TK) domain, aiming at a comprehensive understanding of molecular mechanism and biological implication underlying inhibitor response to ALK TK mutation. We find that (i) the gatekeeper mutation L1196M causes crizotinib resistance by simultaneously increasing and decreasing the binding affinities of, respectively, ATP and inhibitor to ALK, whereas the secondary mutation C1156Y, which is located far away from the ATP-binding site of ALK TK domain, causes the resistance by inducing marked allosteric effect on the site, (ii) the 2nd and 3rd generation kinase inhibitors exhibit relatively high sensitivity towards ALK mutants as compared to 1st generation inhibitors, (iii) the pan-kinase inhibitor staurosporine is insensitive for most mutations due to its high structural compatibility, and (iv) ATP affinity to ALK is generally reduced upon most clinically relevant mutations. Furthermore, we also identify six novel mutation-inhibitor pairs that are potentially associated with drug resistance. In addition, the G1202R and C1156Y mutations are expected to generally cause resistance for many existing inhibitors, since they can address significant effect on the geometric shape and physicochemical property of ALK active pocket.

  12. Tannic acid, a potent inhibitor of epidermal growth factor receptor tyrosine kinase.

    PubMed

    Yang, Er Bin; Wei, Liu; Zhang, Kai; Chen, Yu Zong; Chen, Wei Ning

    2006-03-01

    Increasing evidence supports the hypothesis that tannic acid, a plant polyphenol, exerts anticarcinogenic activity in chemically induced cancers. In the present study, tannic acid was found to strongly inhibit tyrosine kinase activity of epidermal growth factor receptor (EGFr) in vitro (IC50 = 323 nM). In contrast, the inhibition by tannic acid of p60(c-src) tyrosine kinase (IC50 = 14 microM) and insulin receptor tyrosine kinase (IC50 = 5 microM) was much weaker. The inhibition of EGFr tyrosine kinase by tannic acid was competitive with respect to ATP and non-competitive with respect to peptide substrate. In cultured cells, growth factor-induced tyrosine phosphorylation of growth factor receptors, including EGFr, platelet-derived growth factor receptor, and basic fibroblast growth factor receptor, was inhibited by tannic acid. No inhibition of insulin-induced tyrosine phosphorylation of insulin receptor and insulin-receptor substrate-1 was observed. EGF-stimulated growth of HepG2 cells was inhibited in the presence of tannic acid. The inhibition of serine/threonine-specific protein kinases, including cAMP-dependent protein kinase, protein kinase C and mitogen-activated protein kinase, by tannic acid was only detected at relatively high concentration, IC50 being 3, 325 and 142 microM respectively. The molecular modeling study suggested that tannic acid could be docked into the ATP binding pockets of either EGFr or insulin receptor. These results demonstrate that tannic acid is an in vitro potent inhibitor of EGFr tyrosine kinase.

  13. An overview of the binding models of FGFR tyrosine kinases in complex with small molecule inhibitors.

    PubMed

    Cheng, Weiyan; Wang, Mixiang; Tian, Xin; Zhang, Xiaojian

    2017-01-27

    The fibroblast growth factor receptor (FGFR) family receptor tyrosine kinase (RTK) includes four structurally related members, termed as FGFR1, FGFR2, FGFR3, and FGFR4. Given its intimate role in the progression of several solid tumors, excessive FGFR signaling provides an opportunity for anticancer therapy. Along with extensive pharmacological studies validating the therapeutic potential of targeting the FGFRs for cancer treatment, co-crystal structures of FGFRs/inhibitors are continuously coming up to study the mechanism of actions and explore new inhibitors. Herein, we review the reported co-crystals of FGFRs in complex with the corresponding inhibitors, main focusing our attention on the binding models and the pharmacological activities of the inhibitors.

  14. Discovery of GS-9973, a selective and orally efficacious inhibitor of spleen tyrosine kinase.

    PubMed

    Currie, Kevin S; Kropf, Jeffrey E; Lee, Tony; Blomgren, Peter; Xu, Jianjun; Zhao, Zhongdong; Gallion, Steve; Whitney, J Andrew; Maclin, Deborah; Lansdon, Eric B; Maciejewski, Patricia; Rossi, Ann Marie; Rong, Hong; Macaluso, Jennifer; Barbosa, James; Di Paolo, Julie A; Mitchell, Scott A

    2014-05-08

    Spleen tyrosine kinase (Syk) is an attractive drug target in autoimmune, inflammatory, and oncology disease indications. The most advanced Syk inhibitor, R406, 1 (or its prodrug form fostamatinib, 2), has shown efficacy in multiple therapeutic indications, but its clinical progress has been hampered by dose-limiting adverse effects that have been attributed, at least in part, to the off-target activities of 1. It is expected that a more selective Syk inhibitor would provide a greater therapeutic window. Herein we report the discovery and optimization of a novel series of imidazo[1,2-a]pyrazine Syk inhibitors. This work culminated in the identification of GS-9973, 68, a highly selective and orally efficacious Syk inhibitor which is currently undergoing clinical evaluation for autoimmune and oncology indications.

  15. Overcoming Resistance to Inhibitors of the AKT Protein Kinase by Modulation of the Pim Kinase Pathway

    DTIC Science & Technology

    2013-10-01

    translation of the MET receptor tyrosine kinase in prostate cancer. This regulates the activity of the MET/ HGF axis and potentially can affect the...on culture of wild-type DU145 cells in the presence of HGF was enhanced in the Pim-1-overexpressing cells (Fig 6a). This effect was specific as there...was no difference in ERK phosphorylation between the over expressor and wild-type cell lines cultured in HGF . Conversely, in PC3-LN4 cells in

  16. Discovery of 5-(arenethynyl) hetero-monocyclic derivatives as potent inhibitors of BCR-ABL including the T315I gatekeeper mutant.

    PubMed

    Thomas, Mathew; Huang, Wei-Sheng; Wen, David; Zhu, Xiaotian; Wang, Yihan; Metcalf, Chester A; Liu, Shuangying; Chen, Ingrid; Romero, Jan; Zou, Dong; Sundaramoorthi, Raji; Li, Feng; Qi, Jiwei; Cai, Lisi; Zhou, Tianjun; Commodore, Lois; Xu, Qihong; Keats, Jeff; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Marc I; Russian, Karin; Iuliucci, John; Rivera, Victor M; Sawyer, Tomi K; Dalgarno, David C; Clackson, Tim; Shakespeare, William C

    2011-06-15

    Ponatinib (AP24534) was previously identified as a pan-BCR-ABL inhibitor that potently inhibits the T315I gatekeeper mutant, and has advanced into clinical development for the treatment of refractory or resistant CML. In this study, we explored a novel series of five and six membered monocycles as alternate hinge-binding templates to replace the 6,5-fused imidazopyridazine core of ponatinib. Like ponatinib, these monocycles are tethered to pendant toluanilides via an ethynyl linker. Several compounds in this series displayed excellent in vitro potency against both native BCR-ABL and the T315I mutant. Notably, a subset of inhibitors exhibited desirable PK and were orally active in a mouse model of T315I-driven CML.

  17. Designed inhibitor for nuclear localization signal of polo-like kinase 1 induces mitotic arrest.

    PubMed

    Chen, Fangjin; Zhuo, Xiaolong; Qin, Tan; Guo, Xiao; Zhang, Chuanmao; Lai, Luhua

    2016-11-24

    Polo-like kinase 1 (Plk1), a member of polo-like kinase family, regulates multiple essential steps of the cell cycle progression. Plk1 is overexpressed in multiple cancer cell lines and considered to be a prime anticancer target. Plk1 accumulates in the nucleus during S and G2 phases by its bipartite nuclear localization signal (NLS) sequence, which is crucial for Plk1 regulation during normal cell cycle progression. Here, through combined computational and experimental studies, we identified compound D110, which inhibits Plk1 kinase activity with an IC50 of 85 nm and blocks the nuclear localization of Plk1 during S and G2 phases. D110-treated cancer cells were arrested at mitosis with monopolar spindle, indicating the inhibition of the Plk1 kinase activity in cell. As D110 interacts with both the ATP site and the NLS in Plk1, it demonstrates good selectivity toward Plk2 and Plk3. The strategy of simultaneously inhibiting kinase activity and its subcellular translocations offers a novel approach for selective kinase inhibitor design.

  18. Serum concentrations of nitrite and malondialdehyde as markers of oxidative stress in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors

    PubMed Central

    Petrola, Maria Juracy; de Castro, Alana Joselina Montenegro; Pitombeira, Maria Helena da Silva; Barbosa, Maritza Cavalcante; Quixadá, Acy Telles de Souza; Duarte, Fernando Barroso; Gonçalves, Romelia Pinheiro

    2012-01-01

    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. PMID:23125543

  19. [Literature review and presentation of our own research results regarding the effects on bone of tyrosine kinase inhibitors imatinib and nilotinib used in the treatment of oncohematological diseases].

    PubMed

    Kirschner, Gyöngyi; Balla, Bernadett; Kósa, János; Horváth, Péter; Kövesdi, Andrea; Lakatos, Gergely; Takács, István; Nagy, Zsolt; Tóbiás, Bálint; Árvai, Kristóf; Lakatos, Péter

    2016-09-01

    Tyrosine kinase inhibitors are widely used for treatment of certain oncohematological diseases. Several clinical studies have confirmed that specific BCR-ABL tyrosine kinase inhibitors alter the physiological process of bone tissue in a complex and unclearly identified manner. Since these treatments are being given to more and more patients, and the therapy takes decades or lasts even lifelong, it is justifiable to obtain more detailed knowledge of the molecular background of these mechanisms. In this article the authors summarize preliminary research results and human clinical observations on imatinib and nilotinib which are related to bone metabolism, and present the results of their own experiments in in vitro osteoblast cultures. Based on the presented results, the effects of imatinib and nilotinib on bone cells depend on the concentration of imatinib and nilotinib, the maturation stage of the cells and the distribution ratio of receptor tyrosine kinase signaling pathways. In this study the authors firstly prepared a stop-gap, comprehensive review in the Hungarian literature, regarding the effects of tyrosine kinase inhibitors on bone metabolism. In addition they firstly performed whole transcriptome analysis on osteoblasts in order to obtain a better understanding of the cellular molecular mechanisms. Orv. Hetil., 2016, 157(36), 1429-1437.

  20. Crystal Structure of Checkpoint Kinase 2 in Complex with Nsc 109555, a Potent and Selective Inhibitor

    SciTech Connect

    Lountos, George T.; Tropea, Joseph E.; Zhang, Di; Jobson, Andrew G.; Pommier, Yves; Shoemaker, Robert H.; Waugh, David S.

    2009-03-05

    Checkpoint kinase 2 (Chk2), a ser/thr kinase involved in the ATM-Chk2 checkpoint pathway, is activated by genomic instability and DNA damage and results in either arrest of the cell cycle to allow DNA repair to occur or apoptosis if the DNA damage is severe. Drugs that specifically target Chk2 could be beneficial when administered in combination with current DNA-damaging agents used in cancer therapy. Recently, a novel inhibitor of Chk2, NSC 109555, was identified that exhibited high potency (IC{sub 50} = 240 nM) and selectivity. This compound represents a new chemotype and lead for the development of novel Chk2 inhibitors that could be used as therapeutic agents for the treatment of cancer. To facilitate the discovery of new analogs of NSC 109555 with even greater potency and selectivity, we have solved the crystal structure of this inhibitor in complex with the catalytic domain of Chk2. The structure confirms that the compound is an ATP-competitive inhibitor, as the electron density clearly reveals that it occupies the ATP-binding pocket. However, the mode of inhibition differs from that of the previously studied structure of Chk2 in complex with debromohymenialdisine, a compound that inhibits both Chk1 and Chk2. A unique hydrophobic pocket in Chk2, located very close to the bound inhibitor, presents an opportunity for the rational design of compounds with higher binding affinity and greater selectivity.

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

    PubMed Central

    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.

    2015-01-01

    Summary 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. PMID:26320862

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

    PubMed

    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.

  3. Inhibiting EGF receptor or SRC family kinase signaling overcomes BRAF inhibitor resistance in melanoma

    PubMed Central

    Girotti, Maria R; Pedersen, Malin; Sanchez-Laorden, Berta; Viros, Amaya; Turajlic, Samra; Niculescu-Duvaz, Dan; Zambon, Alfonso; Sinclair, John; Hayes, Andrew; Gore, Martin; Lorigan, Paul; Springer, Caroline; Larkin, James; Jorgensen, Claus; Marais, Richard

    2017-01-01

    We generated cell lines resistant to BRAF inhibitors and show that the EGF receptor (EGFR)–SRC family kinase (SFK)–STAT3 signaling pathway was upregulated in these cells. In addition to driving proliferation of resistant cells, this pathway also stimulated invasion and metastasis. EGFR inhibitors cooperated with BRAF inhibitors to block the growth of the resistant cells in vitro and in vivo, and monotherapy with the broad specificity tyrosine kinase inhibitor dasatinib blocked growth and metastasis in vivo. We analyzed tumors from patients with intrinsic or acquired resistance to vemurafenib and observed increased EGFR and SFK activity. Furthermore, dasatinib blocked the growth and metastasis of one of the resistant tumors in immunocompromised mice. Our data shows that BRAF inhibitor-mediated activation of EFGR/SFK/STAT3 signaling can mediate resistance in BRAF mutant melanoma patients. We describe two treatments that appear to overcome this resistance and could deliver therapeutic efficacy in drug-resistant BRAF mutant melanoma patients. PMID:23242808

  4. ZSTK474, a novel phosphatidylinositol 3-kinase inhibitor identified using the JFCR39 drug discovery system.

    PubMed

    Kong, De-xin; Yamori, Takao

    2010-09-01

    JFCR39 is an informatic anticancer drug discovery system that utilizes a panel of 39 human cancer cells coupled with a drug-activity database. This system not only provides disease-oriented information but can also predict the mechanism of action of a given antitumor agent. Development of a phosphatidylinositol 3-kinase (PI3K) inhibitor as an anticancer drug candidate has attracted a great deal of attention from both academia and industry because PI3K is known to be closely involved in carcinogenesis. ZSTK474 was identified as a PI3K inhibitor using JFCR39 system in combination with COMPARE analysis program. These findings were based on the similar fingerprint (growth inhibition profiles for JFCR39 human cancer cell line panel) with that of a classical PI3K inhibitor LY294002. Biochemical experiments confirmed ZSTK474 to be a potent pan-class I PI3K inhibitor, with high selectivity over other classes of PI3K and protein kinases. We previously reported the in vitro and in vivo antitumor efficacy of ZSTK474, together with the G(0)/G(1) arrest and antiangiogenic activity. Here, we review the JFCR39 system and summarize recent studies on PI3K biology and the development of PI3K inhibitors before discussing ZSTK474 in some detail.

  5. Tyrosine kinase inhibitors enhance ciprofloxacin-induced phototoxicity by inhibiting ABCG2.

    PubMed

    Mealey, Katrina L; Dassanayake, Sandamali; Burke, Neal S

    2014-01-01

    The tyrosine kinase inhibitor (TKI) class of anticancer agents inhibits ABCG2-mediated drug efflux. ABCG2 is an important component of the blood-retinal barrier, where it limits retinal exposure to phototoxic compounds such as fluoroquinolone antibiotics. Patients treated with TKIs would be expected to be at greater risk for retinal phototoxicity. Using an in vitro system, our results indicate that the TKIs gefitinib and imatinib abrogate the ability of ABCG2 to protect cells against ciprofloxacin-induced phototoxicity. We conclude that the concurrent administration of ABCG2 inhibitors with photoreactive fluoroquinolone antibiotics may result in retinal damage.

  6. Structural basis for isoform selectivity in a class of benzothiazole inhibitors of phosphoinositide 3-kinase γ.

    PubMed

    Collier, Philip N; Martinez-Botella, Gabriel; Cornebise, Mark; Cottrell, Kevin M; Doran, John D; Griffith, James P; Mahajan, Sudipta; Maltais, François; Moody, Cameron S; Huck, Emilie Porter; Wang, Tiansheng; Aronov, Alex M

    2015-01-08

    Phosphoinositide 3-kinase γ (PI3Kγ) is an attractive target to potentially treat a range of disease states. Herein, we describe the evolution of a reported phenylthiazole pan-PI3K inhibitor into a family of potent and selective benzothiazole inhibitors. Using X-ray crystallography, we discovered that compound 22 occupies a previously unreported hydrophobic binding cleft adjacent to the ATP binding site of PI3Kγ, and achieves its selectivity by exploiting natural sequence differences among PI3K isoforms in this region.

  7. Bruton tyrosine kinase inhibitor ONO/GS-4059: from bench to bedside

    PubMed Central

    Wu, Jingjing; Zhang, Mingzhi; Liu, Delong

    2017-01-01

    The Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been approved for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstroms macroglobulinemia. Acquired resistance to ibrutinib due to BTK C481S mutation has been reported. Mutations in PLC?2 can also mediate resistance to ibrutinib. Untoward effects due to off-target effects are also disadvantages of ibrutinib. More selective and potent BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being investigated. This review summarized the preclinical research and clinical data of ONO/GS-4059. PMID:27776353

  8. Enigmas in tumor resistance to kinase inhibitors and calculation of the drug resistance index for cancer (DRIC).

    PubMed

    Smith, C I Edvard

    2016-11-16

    Darwinian selection is also applicable when antibiotics, the immune system or other host factors shape the repertoire of microorganisms, and similarly, clonal selection is the hallmark of tumor evolution. The ongoing revolution in new anti-cancer treatment modalities, combined with an unprecedented precision in characterizing malignant clones at the level below one percent, profoundly improves the understanding of repertoire-tuning mechanisms. There is no fundamental difference between selection of the tumor cells in the presence, or absence, of therapy. However, under treatment the influence of a single agent can be measured, simplifying the analysis. Because of their beneficial and selective therapeutic effect, the focus in this review is set on protein kinase inhibitors (PKIs), predominantly tyrosine kinase inhibitors (TKIs). This is one of the most rapidly growing families of novel cancer medicines. In order to limit the number of drugs, the following representative target kinases are included: ALK, BCR-ABL, BRAF, BTK, and EGFR. A key therapeutic challenge is how to reduce tumor growth after treatment, since this is rate-limiting for the generation and expansion of more malignant escape mutants. Thus, upon efficient treatment, tumor cell loss often enables a profoundly increased growth rate among resistant cells. Strategies to reduce this risk, such as concomitant, competitive outgrowth of non-transformed cells, are described. Seven parameters: 1. Drug type, 2. tumor type, 3. presence of metastases or phenotypic change, 4. tumor cell number, 5. net growth rate (proliferation minus cell death), 6. inherited genetic- and 7. epigenetic- variations are crucial for drug responses. It is envisaged that it might become possible to calculate a clinically relevant Drug Resistance Index for Cancer (DRIC) for each patient.

  9. Emission Tuning of Fluorescent Kinase Inhibitors: Conjugation Length and Substituent Effects

    PubMed Central

    2015-01-01

    Fluorescent N-phenyl-4-aminoquinazoline probes targeting the ATP-binding pocket of the ERBB family of receptor tyrosine kinases are reported. Extension of the aromatic quinazoline core with fluorophore “arms” through substitution at the 6- position of the quinazoline core with phenyl, styryl, and phenylbutadienyl moieties was predicted by means of TD-DFT calculations to produce probes with tunable photoexcitation energies and excited states possessing charge-transfer character. Optical spectroscopy identified several synthesized probes that are nonemissive in aqueous solutions and exhibit emission enhancements in solvents of low polarity, suggesting good performance as turn-on fluorophores. Ligand-induced ERBB2 phosphorylation assays demonstrate that despite chemical modification to the quinazoline core these probes still function as ERBB2 inhibitors in MCF7 cells. Two probes were found to exhibit ERBB2-induced fluorescence, demonstrating the utility of these probes as turn-on, fluoroescent kinase inhibitors. PMID:24784897

  10. Inhibitors of the Polo-Box Domain of Polo-Like Kinase 1.

    PubMed

    Berg, Angela; Berg, Thorsten

    2016-04-15

    Polo-like kinase 1 (Plk1), a key player in mitosis, is overexpressed in a wide range of tumor types and has been validated as a target for tumor therapy. In addition to its N-terminal kinase domain, Plk1 harbors a C-terminal protein-protein interaction domain, referred to as the polo-box domain (PBD). Because the PBD is unique to the five-member family of polo-like kinases, and its inhibition is sufficient to inhibit the enzyme, the Plk1 PBD is an attractive target for the inhibition of Plk1 function. Although peptide-based inhibitors are invaluable tools for elucidating the nature of the binding interface, small molecules are better suited for the induction of mitotic arrest and apoptosis in tumor cells by Plk1 inhibition. This review describes the considerable progress that has been made in developing small-molecule and peptide-based inhibitors of the Plk1 PBD.

  11. Initial testing of VS-4718, a novel inhibitor of focal adhesion kinase (FAK), against pediatric tumor models by the Pediatric Preclinical Testing Program.

    PubMed

    Kurmasheva, Raushan T; Gorlick, Richard; Kolb, E Anders; Keir, Stephen T; Maris, John M; Lock, Richard B; Carol, Hernan; Kang, Min; Reynolds, C Patrick; Wu, Jianrong; Houghton, Peter J; Smith, Malcolm A

    2017-04-01

    VS-4718, a novel inhibitor of focal adhesion kinase (FAK), was tested against the Pediatric Preclinical Testing Program's (PPTP's) in vitro cell line panel and showed a median relative IC50 of 1.22 μM. VS-4718 was tested in vivo against the PPTP xenograft models using a dose of 50 mg/kg administered by the oral route twice daily for 21 days. VS-4718 induced significant differences in an event-free survival distribution compared with control in 18 of 36 of the evaluable solid tumor xenografts and in 0 of 8 acute lymphoblastic leukemia (ALL) xenografts, but no xenograft lines showed tumor regression. Future plans include further evaluation of the role of FAK inhibition in combination with ABL kinase inhibitors for Ph(+) ALL.

  12. Combination treatment of prostate cancer with FGF receptor and AKT kinase inhibitors

    PubMed Central

    Feng, Shu; Shao, Longjiang; Castro, Patricia; Coleman, Ilsa; Nelson, Peter S; Smith, Paul D; Davies, Barry R; Ittmann, Michael

    2017-01-01

    Activation of the PI3K/AKT pathway occurs in the vast majority of advanced prostate cancers (PCas). Activation of fibroblast growth factor receptor (FGFR) signaling occurs in a wide variety of malignancies, including PCa. RNA-Seq of castration resistant PCa revealed expression of multiple FGFR signaling components compatible with FGFR signaling in all cases, with multiple FGF ligands expressed in 90% of cases. Immunohistochemistry confirmed FGFR signaling in the majority of xenografts and advanced PCas. AZD5363, an AKT kinase inhibitor and AZD4547, a FGFR kinase inhibitor are under active clinical development. We therefore sought to determine if these two drugs have additive effects in PCa models. The effect of both agents, singly and in combination was evaluated in a variety of PCa cell lines in vitro and in vivo. All cell lines tested responded to both drugs with decreased invasion, soft agar colony formation and growth in vivo, with additive effects seen with combination treatment. Activation of the FGFR, AKT, ERK and STAT3 pathways was examined in treated cells. AZD5363 inhibited AKT signaling and increased FGFR1 signaling, which partially compensated for decreased AKT kinase activity. While AZD4547 could effectively block the ERK pathway, combination treatment was needed to completely block STAT3 activation. Thus combination treatment with AKT and FGFR kinase inhibitors have additive effects on malignant phenotypes in vitro and in vivo by inhibiting multiple signaling pathways and mitigating the compensatory upregulation of FGFR signaling induced by AKT kinase inhibition. Our studies suggest that co-targeting these pathways may be efficacious in advanced PCa. PMID:28008155

  13. Tyrosine kinase inhibitors as modulators of ABC transporter-mediated drug resistance

    PubMed Central

    Shukla, Suneet; Chen, Zhe-Sheng; Ambudkar, Suresh V.

    2012-01-01

    Tyrosine kinases (TKs) are involved in key signaling events/pathways that regulate cancer cell proliferation, apoptosis, angiogenesis and metastasis. Deregulated activity of TKs has been implicated in several types of cancers. In recent years, tyrosine kinase inhibitors (TKIs) have been developed to inhibit specific kinases whose constitutive activity results in specific cancer types. These TKIs have been found to demonstrate effective anticancer activity and some of them have been approved by the Food and Drug Administration for clinical use or are in clinical trials. However, these targeted therapeutic agents are also transported by ATP-binding cassette (ABC) transporters, resulting in altered pharmacokinetics or development of resistance to these drugs in cancer patients. This review covers the recent findings on the interactions of clinically important TKIs with ABC drug transporters. Future research efforts in the development of novel TKIs with specific targets, seeking improved activity, should consider these underlying causes of resistance to TKIs in cancer cells. PMID:22325423

  14. Discovery of Isonicotinamides as Highly Selective, Brain Penetrable, and Orally Active Glycogen Synthase Kinase-3 Inhibitors.

    PubMed

    Luo, Guanglin; Chen, Ling; Burton, Catherine R; Xiao, Hong; Sivaprakasam, Prasanna; Krause, Carol M; Cao, Yang; Liu, Nengyin; Lippy, Jonathan; Clarke, Wendy J; Snow, Kimberly; Raybon, Joseph; Arora, Vinod; Pokross, Matt; Kish, Kevin; Lewis, Hal A; Langley, David R; Macor, John E; Dubowchik, Gene M

    2016-02-11

    GSK-3 is a serine/threonine kinase that has numerous substrates. Many of these proteins are involved in the regulation of diverse cellular functions, including metabolism, differentiation, proliferation, and apoptosis. Inhibition of GSK-3 may be useful in treating a number of diseases including Alzheimer's disease (AD), type II diabetes, mood disorders, and some cancers, but the approach poses significant challenges. Here, we present a class of isonicotinamides that are potent, highly kinase-selective GSK-3 inhibitors, the members of which demonstrated oral activity in a triple-transgenic mouse model of AD. The remarkably high kinase selectivity and straightforward synthesis of these compounds bode well for their further exploration as tool compounds and therapeutics.

  15. Synthesis and biological evaluation of 2,4-diaminopyrimidines as selective Aurora A kinase inhibitors.

    PubMed

    Qin, Wen-Wen; Sang, Chun-Yan; Zhang, Lin-Lin; Wei, Wei; Tian, Heng-Zhi; Liu, Huan-Xiang; Chen, Shi-Wu; Hui, Ling

    2015-05-05

    The Aurora kinases are a family of serine/threonine kinases that interact with components of the mitotic apparatus and serve as potential therapeutic targets in oncology. Here we synthesized 15 2,4-diaminopyrimidines and evaluated their biological activities, including antiproliferation, inhibition against Aurora kinases and cell cycle effects. These compounds generally exhibited more potent cytotoxicity against tumor cell lines compared with the VX-680 control, especially compound 11c, which showed the highest cytotoxicities, with IC50 values of 0.5-4.0 μM. Compound 11c had more than 35-fold more selectivity for Aurora A over Aurora B, and molecular docking analysis indicated that compound 11c form better interaction with Aurora A both from the perspective of structure and energy. Furthermore, compound 11c induced G2/M cell cycle arrest in HeLa cells. This series of compounds has the potential for further development as selective Aurora A inhibitors for anticancer activity.

  16. Fragment-Based Discovery of Type I Inhibitors of Maternal Embryonic Leucine Zipper Kinase

    PubMed Central

    2014-01-01

    Fragment-based drug design was successfully applied to maternal embryonic leucine zipper kinase (MELK). A low affinity (160 μM) fragment hit was identified, which bound to the hinge region with an atypical binding mode, and this was optimized using structure-based design into a low-nanomolar and cell-penetrant inhibitor, with a good selectivity profile, suitable for use as a chemical probe for elucidation of MELK biology. PMID:25589925

  17. In Vitro High Throughput Screening, What Next? Lessons from the Screening for Aurora Kinase Inhibitors

    PubMed Central

    Hoang, Thi-My-Nhung; Vu, Hong-Lien; Le, Ly-Thuy-Tram; Nguyen, Chi-Hung; Molla, Annie

    2014-01-01

    Based on in vitro assays, we performed a High Throughput Screening (HTS) to identify kinase inhibitors among 10,000 small chemical compounds. In this didactic paper, we describe step-by-step the approach to validate the hits as well as the major pitfalls encountered in the development of active molecules. We propose a decision tree that could be adapted to most in vitro HTS. PMID:24833340

  18. Role of Tyrosine Kinase Inhibitors in Indolent and Other Mature B-Cell Neoplasms

    PubMed Central

    Kutsch, Nadine; Marks, Reinhard; Ratei, Richard; Held, Thomas K; Schmidt-Hieber, Martin

    2015-01-01

    Targeting tyrosine kinases represents a highly specific treatment approach for different malignancies. This also includes non-Hodgkin lymphoma since it is well known that these enzymes are frequently involved in the lymphomagenesis. Hereby, tyrosine kinases might either be dysregulated intrinsically or be activated within signal transduction pathways leading to tumor survival and growth. Among others, Bruton’s tyrosine kinase (Btk) is of particular interest as a potential therapeutic target. Btk is stimulated by B-cell receptor signaling and activates different transcription factors such as nuclear factor κB. The Btk inhibitor ibrutinib has been approved for the treatment of chronic lymphocytic leukemia and mantle-cell lymphoma recently. Numerous clinical trials evaluating this agent in different combinations (eg, with rituximab or classical chemotherapeutic agents) as a treatment option for aggressive and indolent lymphoma are under way. Here, we summarize the role of tyrosine kinase inhibitors in the treatment of indolent and other non-Hodgkin lymphomas (eg, mantle-cell lymphoma). PMID:26327780

  19. Perspectives for the use of structural information and chemical genetics to develop inhibitors of Janus kinases

    PubMed Central

    Haan, Claude; Behrmann, Iris; Haan, Serge

    2010-01-01

    Abstract Gain-of-function mutations in the genes encoding Janus kinases have been discovered in various haematologic diseases. Jaks are composed of a FERM domain, an SH2 domain, a pseudokinase domain and a kinase domain, and a complex interplay of the Jak domains is involved in regulation of catalytic activity and association to cytokine receptors. Most activating mutations are found in the pseudokinase domain. Here we present recently discovered mutations in the context of our structural models of the respective domains. We describe two structural hotspots in the pseudokinase domain of Jak2 that seem to be associated either to myeloproliferation or to lymphoblastic leukaemia, pointing at the involvement of distinct signalling complexes in these disease settings. The different domains of Jaks are discussed as potential drug targets. We present currently available inhibitors targeting Jaks and indicate structural differences in the kinase domains of the different Jaks that may be exploited in the development of specific inhibitors. Moreover, we discuss recent chemical genetic approaches which can be applied to Jaks to better understand the role of these kinases in their biological settings and as drug targets. PMID:20132407

  20. Discovery of Novel Fibroblast Growth Factor Receptor 1 Kinase Inhibitors by Structure-Based Virtual Screening

    SciTech Connect

    Ravindranathan, K.; Mandiyan, V; Ekkati, A; Bae, J; Schlessinger, J; Jorgensen, W

    2010-01-01

    Fibroblast growth factors (FGFs) play important roles in embryonic development, angiogenesis, wound healing, and cell proliferation and differentiation. In search of inhibitors of FGFR1 kinase, 2.2 million compounds were docked into the ATP binding site of the protein. A co-crystal structure, which shows two alternative conformations for the nucleotide binding loop, is reported. Docking was performed on both conformations and, ultimately, 23 diverse compounds were purchased and assayed. Following hit validation, two compounds 10 and 16, a benzylidene derivative of pseudothiohydantoin and a thienopyrimidinone derivative, respectively, were discovered that inhibit FGFR1 kinase with IC{sub 50} values of 23 and 50 {micro}M. Initial optimization of 16 led to the more unsaturated 40, which has significantly enhanced potency, 1.9 {micro}M. The core structures represent new structural motifs for FGFR1 kinase inhibitors. The study also illustrates complexities associated with the choice of protein structures for docking, possible use of multiple kinase structures to seek selectivity, and hit identification.

  1. Transcriptional upregulation of the human MRP2 gene expression by serine/threonine protein kinase inhibitors.

    PubMed

    Pułaski, L; Szemraj, J; Uchiumi, T; Kuwano, M; Bartosz, G

    2005-01-01

    Transcriptional regulation by cellular signalling pathways of multidrug resistance proteins that pump anticancer drugs out of cells is one of key issues in the development of the multidrug resistance phenotype. In our study, we have used the reporter gene approach as well as determination of mRNA levels in two cancer cell lines of human origin, MCF-7 and A549, to study the regulation of multidrug resistance proteins 2 and 3 (MRP2 AND MRP3) by serine/threonine protein kinases. Since a prototypic PKC inducer, PMA, caused a marked upregulation of transcription from both human MRP2 and MRP3 promoters, a role for PKC isoforms in positive control of expression of these proteins could be postulated. Interestingly, broad-spectrum serine-threonine protein kinase inhibitors which also inhibit PKC, staurosporine and H-7, stimulated expression from the MRP2 promoter instead of inhibiting it. This effect was not seen for MRP3. MRP2 induction by staurosporine and H-7 was shown to have phenotypic consequences in whole cells, rendering them more resistant to etoposide and increasing their ability to export calcein through the plasma membrane. These results point to the involvement of serine/threonine protein kinases in negative regulation of the human MRP2 gene and to the necessity of testing novel anti-cancer drugs acting as protein kinase inhibitors with regard to their potential ability to induce multidrug resistance.

  2. High-content screen using zebrafish (Danio rerio) embryos identifies a novel kinase activator and inhibitor.

    PubMed

    Geldenhuys, Werner J; Bergeron, Sadie A; Mullins, Jackie E; Aljammal, Rowaa; Gaasch, Briah L; Chen, Wei-Chi; Yun, June; Hazlehurst, Lori A

    2017-02-28

    In this report we utilized zebrafish (Danio rerio) embryos in a phenotypical high-content screen (HCS) to identify novel leads in a cancer drug discovery program. We initially validated our HCS model using the flavin adenosine dinucleotide (FAD) containing endoplasmic reticulum (ER) enzyme, endoplasmic reticulum oxidoreductase (ERO1) inhibitor EN460. EN460 showed a dose response effect on the embryos with a dose of 10μM being significantly lethal during early embryonic development. The HCS campaign which employed a small library identified a promising lead compound, a naphthyl-benzoic acid derivative coined compound 1 which had significant dosage and temporally dependent effects on notochord and muscle development in zebrafish embryos. Screening a 369 kinase member panel we show that compound 1 is a PIM3 kinase inhibitor (IC50=4.078μM) and surprisingly a DAPK1 kinase agonist/activator (EC50=39.525μM). To our knowledge this is the first example of a small molecule activating DAPK1 kinase. We provide a putative model for increased phosphate transfer in the ATP binding domain when compound 1 is virtually docked with DAPK1. Our data indicate that observable phenotypical changes can be used in future zebrafish screens to identify compounds acting via similar molecular signaling pathways.

  3. Discovery of a potent, selective, and orally bioavailable pyridinyl-pyrimidine phthalazine aurora kinase inhibitor.

    PubMed

    Cee, Victor J; Schenkel, Laurie B; Hodous, Brian L; Deak, Holly L; Nguyen, Hanh N; Olivieri, Philip R; Romero, Karina; Bak, Annette; Be, Xuhai; Bellon, Steve; Bush, Tammy L; Cheng, Alan C; Chung, Grace; Coats, Steve; Eden, Patrick M; Hanestad, Kelly; Gallant, Paul L; Gu, Yan; Huang, Xin; Kendall, Richard L; Lin, Min-Hwa Jasmine; Morrison, Michael J; Patel, Vinod F; Radinsky, Robert; Rose, Paul E; Ross, Sandra; Sun, Ji-Rong; Tang, Jin; Zhao, Huilin; Payton, Marc; Geuns-Meyer, Stephanie D

    2010-09-09

    The discovery of aurora kinases as essential regulators of cell division has led to intense interest in identifying small molecule aurora kinase inhibitors for the potential treatment of cancer. A high-throughput screening effort identified pyridinyl-pyrimidine 6a as a moderately potent dual inhibitor of aurora kinases -A and -B. Optimization of this hit resulted in an anthranilamide lead (6j) that possessed improved enzyme and cellular activity and exhibited a high level of kinase selectivity. However, this anthranilamide and subsequent analogues suffered from a lack of oral bioavailability. Converting the internally hydrogen-bonded six-membered pseudo-ring of the anthranilamide to a phthalazine (8a-b) led to a dramatic improvement in oral bioavailability (38-61%F) while maintaining the potency and selectivity characteristics of the anthranilamide series. In a COLO 205 tumor pharmacodynamic assay measuring phosphorylation of the aurora-B substrate histone H3 at serine 10 (p-histone H3), oral administration of 8b at 50 mg/kg demonstrated significant reduction in tumor p-histone H3 for at least 6 h.

  4. Effects of tyrosine kinase inhibitor on the motility and ATP concentrations of fowl spermatozoa.

    PubMed

    Ashizawa, K; Higashio, M; Tsuzuki, Y

    1998-02-01

    The possible role of tyrosine kinase in the regulation of fowl sperm motility was investigated by using a stable analogue of erbstatin, methyl 2,5-dihydroxycinnamate (2,5-MeC), a specific inhibitor of tyrosine kinase. This inhibited the motility of intact spermatozoa at 30 degrees C in a dose-dependent manner. In contrast, the motility of demembranated spermatozoa was not inhibited by the same concentrations of 2,5-MeC. At 40 degrees C, both intact and demembranated spermatozoa were almost immotile with or without 2,5-MeC. Additionally, intact spermatozoa, stimulated by the addition of Ca2+ or calyculin A, a specific inhibitor of protein phosphatases, lost their motility with the subsequent addition of 2,5-MeC at 40 degrees C. However, unlike the motility, the ATP concentrations of spermatozoa were maintained in about 30-35 nmol ATP/10(9) cells during these incubation periods. The activity of tyrosine kinase of spermatozoa at 30 degrees C, estimated by measuring the phosphorylation of a synthetic peptide substrate, RR-SRC, was 0.17 pmol/min per milligram of protein. This activity was lower than that of fowl testes or chick brain but higher than that of chick liver. These results suggest that tyrosine kinase activity, which is not retained in the axoneme and/or accessory cytoskeletal components, may be involved in the maintenance of flagellar movement of fowl spermatozoa at 30 degrees C.

  5. Regulation of actin polymerization and adhesion-dependent cell edge protrusion by the Abl-related gene (Arg) tyrosine kinase and N-WASp.

    PubMed

    Miller, Matthew M; Lapetina, Stefanie; MacGrath, Stacey M; Sfakianos, Mindan K; Pollard, Thomas D; Koleske, Anthony J

    2010-03-16

    Extracellular cues stimulate the Abl family nonreceptor tyrosine kinase Arg to promote actin-based cell edge protrusions. Several Arg-interacting proteins are potential links to the actin cytoskeleton, but exactly how Arg stimulates actin polymerization and cellular protrusion has not yet been fully elucidated. We used affinity purification to identify N-WASp as a novel binding partner of Arg. N-WASp activates the Arp2/3 complex and is an effector of Abl. We find that the Arg SH3 domain binds directly to N-WASp. Arg phosphorylates N-WASp on Y256, modestly increasing the affinity of Arg for N-WASp, an interaction that does not require the Arg SH2 domain. The Arg SH3 domain stimulates N-WASp-dependent actin polymerization in vitro, and Arg phosphorylation of N-WASp weakly stimulates this effect. Arg and N-WASp colocalize to adhesion-dependent cell edge protrusions in vivo. The cell edge protrusion defects of arg-/- fibroblasts can be complemented by re-expression of an Arg-yellow fluorescent protein (YFP) fusion, but not by an N-WASp binding-deficient Arg SH3 domain point mutant. These results suggest that Arg promotes actin-based protrusions in response to extracellular stimuli through phosphorylation of and physical interactions with N-WASp.

  6. In silico 3D structure modeling and inhibitor binding studies of human male germ cell-associated kinase.

    PubMed

    Tanneeru, Karunakar; Balla, Ashok Raja; Guruprasad, Lalitha

    2015-01-01

    Human male germ cell-associated kinase (hMAK) is an androgen-inducible gene in prostate epithelial cells, and it acts as a coactivator of androgen receptor signaling in prostate cancer. The 3D structure of the hMAK kinase was modeled based on the crystal structure of CDK2 kinase using comparative modeling methods, and the ATP-binding site was characterized. We have collected five inhibitors of hMAK from the literature and docked into the ATP-binding site of the kinase domain. Solvated interaction energies (SIE) of inhibitor binding are calculated from the molecular dynamics simulations trajectories of protein-inhibitor complexes. The contribution from each active site residue in hMAK toward inhibitor binding revealed the nature and extent of interactions between inhibitors and individual residues. The main chain atoms of Met79 invariably form hydrogen bonds with all five inhibitors. The amino acids Leu7, Val15, and Leu129 stabilize the inhibitors via CH-pi interactions. The Asp140 in the active site and Glu77 in hinge region show characteristic hydrogen bonding interactions with inhibitors. From SIE, the residue-wise interactions revealed the nature of non-bonding contacts and modifications required to increase the inhibitor activity. Our work provides 3D model structure of hMAK and molecular basis for the mechanisms of hMAK inhibition at atomic level that aid in designing new potent inhibitors.

  7. Aurora kinase inhibitor nanoparticles target tumors with favorable therapeutic index in vivo.

    PubMed

    Ashton, Susan; Song, Young Ho; Nolan, Jim; Cadogan, Elaine; Murray, Jim; Odedra, Rajesh; Foster, John; Hall, Peter A; Low, Susan; Taylor, Paula; Ellston, Rebecca; Polanska, Urszula M; Wilson, Joanne; Howes, Colin; Smith, Aaron; Goodwin, Richard J A; Swales, John G; Strittmatter, Nicole; Takáts, Zoltán; Nilsson, Anna; Andren, Per; Trueman, Dawn; Walker, Mike; Reimer, Corinne L; Troiano, Greg; Parsons, Donald; De Witt, David; Ashford, Marianne; Hrkach, Jeff; Zale, Stephen; Jewsbury, Philip J; Barry, Simon T

    2016-02-10

    Efforts to apply nanotechnology in cancer have focused almost exclusively on the delivery of cytotoxic drugs to improve therapeutic index. There has been little consideration of molecularly targeted agents, in particular kinase inhibitors, which can also present considerable therapeutic index limitations. We describe the development of Accurin polymeric nanoparticles that encapsulate the clinical candidate AZD2811, an Aurora B kinase inhibitor, using an ion pairing approach. Accurins increase biodistribution to tumor sites and provide extended release of encapsulated drug payloads. AZD2811 nanoparticles containing pharmaceutically acceptable organic acids as ion pairing agents displayed continuous drug release for more than 1 week in vitro and a corresponding extended pharmacodynamic reduction of tumor phosphorylated histone H3 levels in vivo for up to 96 hours after a single administration. A specific AZD2811 nanoparticle formulation profile showed accumulation and retention in tumors with minimal impact on bone marrow pathology, and resulted in lower toxicity and increased efficacy in multiple tumor models at half the dose intensity of AZD1152, a water-soluble prodrug of AZD2811. These studies demonstrate that AZD2811 can be formulated in nanoparticles using ion pairing agents to give improved efficacy and tolerability in preclinical models with less frequent dosing. Accurins specifically, and nanotechnology in general, can increase the therapeutic index of molecularly targeted agents, including kinase inhibitors targeting cell cycle and oncogenic signal transduction pathways, which have to date proved toxic in humans.

  8. Novel, potent and selective inhibitors of protein kinase C show oral anti-inflammatory activity.

    PubMed

    Nixon, J S; Bishop, J; Bradshaw, D; Davis, P D; Hill, C H; Elliott, L H; Kumar, H; Lawton, G; Lewis, E J; Mulqueen, M

    1991-01-01

    Clarification of the precise role of protein kinase C (PKC) in cellular functional responses has been hampered by a lack of potent, selective inhibitors. The structural lead provided by staurosporine, a potent but non-selective protein kinase (PK) inhibitor, was used to derive a series of bis(indolyl)maleimides of which the most potent, Ro 31-8425 (I50: PKC = 8 nM) showed 350-fold selectivity for PKC over cAMP-dependent protein kinase. Ro 31-8425 antagonised cellular processes triggered by phorbol esters (potent, specific PKC activators) and inhibited the allogeneic mixed lymphocyte reaction, suggesting a role for PKC in T-cell activation. Methylation of the primary amine in Ro 31-8425 produced an analogue. Ro 31-8830 which, when administered orally, produced a dose-dependent inhibition of a phorbol ester-induced paw oedema in mice (minimum effective dose = 15 mg/kg). Ro 31-8830 also selectively inhibited the secondary inflammation in a developing adjuvant arthritis model in the rat. The results presented here suggest that these selective inhibitors of PKC may have therapeutic value in the treatment of T-cell-mediated autoimmune diseases.

  9. Casein kinase 1δ/ε inhibitor PF-5006739 attenuates opioid drug-seeking behavior.

    PubMed

    Wager, Travis T; Chandrasekaran, Ramalakshmi Y; Bradley, Jenifer; Rubitski, David; Berke, Helen; Mente, Scot; Butler, Todd; Doran, Angela; Chang, Cheng; Fisher, Katherine; Knafels, John; Liu, Shenping; Ohren, Jeff; Marconi, Michael; DeMarco, George; Sneed, Blossom; Walton, Kevin; Horton, David; Rosado, Amy; Mead, Andy

    2014-12-17

    Casein kinase 1 delta (CK1δ) and casein kinase 1 epsilon (CK1ε) inhibitors are potential therapeutic agents for a range of psychiatric disorders. The feasibility of developing a CNS kinase inhibitor has been limited by an inability to identify safe brain-penetrant compounds with high kinome selectivity. Guided by structure-based drug design, potent and selective CK1δ/ε inhibitors have now been identified that address this gap, through the design and synthesis of novel 4-[4-(4-fluorophenyl)-1-(piperidin-4-yl)-1H-imidazol-5-yl]pyrimidin-2-amine derivatives. PF-5006739 (6) possesses a desirable profile, with low nanomolar in vitro potency for CK1δ/ε (IC50 = 3.9 and 17.0 nM, respectively) and high kinome selectivity. In vivo, 6 demonstrated robust centrally mediated circadian rhythm phase-delaying effects in both nocturnal and diurnal animal models. Further, 6 dose-dependently attenuated opioid drug-seeking behavior in a rodent operant reinstatement model in animals trained to self-administer fentanyl. Collectively, our data supports further development of 6 as a promising candidate to test the hypothesis of CK1δ/ε inhibition in treating multiple indications in the clinic.

  10. The discovery of novel vascular endothelial growth factor receptor tyrosine kinases inhibitors: pharmacophore modeling, virtual screening and docking studies.

    PubMed

    Yu, Hui; Wang, Zhanli; Zhang, Liangren; Zhang, Jufeng; Huang, Qian

    2007-03-01

    We have applied pharmacophore generation, database searching and docking methodologies to discover new structures for the design of vascular endothelial growth factor receptors, the tyrosine kinase insert domain-containing receptor kinase inhibitors. The chemical function based pharmacophore models were built for kinase insert domain-containing receptor kinase inhibitors from a set of 10 known inhibitors using the algorithm HipHop, which is implemented in the CATALYST software. The highest scoring HipHop model consists of four features: one hydrophobic, one hydrogen bond acceptor, one hydrogen bond donor and one ring aromatic function. Using the algorithm CatShape within CATALYST, the bound conformation of 4-amino-furo [2, 3-d] pyrimidine binding to kinase insert domain-containing receptor kinase was used to generate a shape query. A merged shape and hypothesis query that is in an appropriate alignment was then built. The combined shape and hypothesis model was used as a query to search Maybridge database for other potential lead compounds. A total of 39 compounds were retrieved as hits. The hits obtained were docked into kinase insert domain-containing receptor kinase active site. One novel potential lead was proposed based on CATALYST fit value, LigandFit docking scores, and examination of how the hit retain key interactions known to be required for kinase binding. This compound inhibited vascular endothelial growth factor stimulated kinase insert domain-containing receptor phosphorylation in human umbilical vein endothelial cells.

  11. Activation of HER3 Interferes with Antitumor Effects of Axl Receptor Tyrosine Kinase Inhibitors: Suggestion of Combination Therapy1

    PubMed Central

    Torka, Robert; Pénzes, Kinga; Gusenbauer, Simone; Baumann, Christine; Szabadkai, István; Őrfi, Lászlȯ; Kéri, György; Ullrich, Axel

    2014-01-01

    The Axl receptor tyrosine kinase (RTK) has been established as a strong candidate for targeted therapy of cancer. However, the benefits of targeted therapies are limited due to acquired resistance and activation of alternative RTKs. Therefore, we asked if cancer cells are able to overcome targeted Axl therapies. Here, we demonstrate that inhibition of Axl by short interfering RNA or the tyrosine kinase inhibitor (TKI) BMS777607 induces the expression of human epidermal growth factor receptor 3 (HER3) and the neuregulin 1(NRG1)–dependent phosphorylation of HER3 in MDA-MB231 and Ovcar8 cells. Moreover, analysis of 20 Axl-expressing cancer cell lines of different tissue origin indicates a low basal phosphorylation of RAC-α serine/threonine-protein kinase (AKT) as a general requirement for HER3 activation on Axl inhibition. Consequently, phosphorylation of AKT arises as an independent biomarker for Axl treatment. Additionally, we introduce phosphorylation of HER3 as an independent pharmacodynamic biomarker for monitoring of anti-Axl therapy response. Inhibition of cell viability by BMS777607 could be rescued by NRG1-dependent activation of HER3, suggesting an escape mechanism by tumor microenvironment. The Axl-TKI MPCD84111 simultaneously blocked Axl and HER2/3 signaling and thereby prohibited HER3 feedback activation. Furthermore, dual inhibition of Axl and HER2/3 using BMS777607 and lapatinib led to a significant inhibition of cell viability in Axl-expressing MDA-MB231 and Ovcar8 cells. Therefore, we conclude that, in patient cohorts with expression of Axl and low basal activity of AKT, a combined inhibition of Axl and HER2/3 kinase would be beneficial to overcome acquired resistance to Axl-targeted therapies. PMID:24862757

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

    PubMed

    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.

  13. Novel Kinase Inhibitors Targeting the PH Domain of AKT for Preventing and Treating Cancer | NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute's Medical Oncology Branch is seeking statements of capability or interest from parties interested in licensing and co-development collaborative research to further develop, evaluate, or commercialize novel kinase inhibitors targeting the PH domain of AKT.

  14. Pyrazolo[3,4-d]pyrimidine Prodrugs: Strategic Optimization of the Aqueous Solubility of Dual Src/Abl Inhibitors

    PubMed Central

    2013-01-01

    Design and synthesis of prodrugs of promising drug candidates represents a valid strategy to overcome the lack of favorable ADME properties, in particular aqueous solubility and bioavailability. We report herein the successful application of this strategy with two representative pyrazolo[3,4-d]pyrimidine derivatives (1 and 2), which led to the development of the corresponding and highly water-soluble antitumor prodrugs (7 and 8). In vitro studies confirmed a significant improvement of aqueous solubility and, for compound 8, good plasma stability, suggesting superior in vivo bioavailability. As expected, the uncleaved water-soluble prodrugs 7 and 8 showed no activity toward the enzymatic targets (c-Src and c-Abl) but revealed promising antiproliferative activity in myeloid cell lines, as a consequence of the in vitro hydrolysis of the selected solubilizing moiety, followed by the release of the active compounds (1 and 2). PMID:24900720

  15. Effect of Narrow Spectrum Versus Selective Kinase Inhibitors on the Intestinal Proinflammatory Immune Response in Ulcerative Colitis

    PubMed Central

    Biancheri, Paolo; Foster, Martyn R.; Fyfe, Matthew C. T.; MacDonald, Thomas T.; Sirohi, Sameer; Solanke, Yemisi; Wood, Eleanor; Rowley, Adele; Webber, Steve

    2016-01-01

    Background: Kinases are key mediators of inflammation, highlighting the potential of kinase inhibitors as treatments for inflammatory disorders. Selective kinase inhibitors, however, have proved disappointing, particularly in the treatment of rheumatoid arthritis and inflammatory bowel disease. Consequently, to improve efficacy, attention has turned to multikinase inhibition. Methods: The activity of a narrow spectrum kinase inhibitor, TOP1210, has been compared with selective kinase inhibitors (BIRB-796, dasatinib and BAY-61-3606) in a range of kinase assays, inflammatory cell assays, and in inflamed biopsies from patients with ulcerative colitis (UC). Effects on recombinant P38α, Src, and Syk kinase activities were assessed using Z-lyte assays (Invitrogen, Paisley, United Kingdom). Anti-inflammatory effects were assessed by measurement of proinflammatory cytokine release from peripheral blood mononuclear cells, primary macrophages, HT29 cells, inflamed colonic UC biopsies, and myofibroblasts isolated from inflamed colonic UC mucosa. Results: TOP1210 potently inhibits P38α, Src, and Syk kinase activities. Similarly, TOP1210 demonstrates potent inhibitory activity against proinflammatory cytokine release in each of the cellular assays and the inflamed colonic UC biopsies and myofibroblasts isolated from inflamed colonic UC mucosa. Generally, the selective kinase inhibitors showed limited and weaker activity in the cellular assays compared with the broad inhibitory profile of TOP1210. However, combination of the selective inhibitors led to improved efficacy and potency in both cellular and UC biopsy assays. Conclusions: Targeted, multikinase inhibition with TOP1210 leads to a broad efficacy profile in both the innate and adaptive immune responses, with significant advantages over existing selective kinase approaches, and potentially offers a much improved therapeutic benefit in inflammatory bowel disease. PMID:27104822

  16. Structure-based design and synthesis of potent benzothiazole inhibitors of interleukin-2 inducible T cell kinase (ITK).

    PubMed

    MacKinnon, Colin H; Lau, Kevin; Burch, Jason D; Chen, Yuan; Dines, Jonathon; Ding, Xiao; Eigenbrot, Charles; Heifetz, Alexander; Jaochico, Allan; Johnson, Adam; Kraemer, Joachim; Kruger, Susanne; Krülle, Thomas M; Liimatta, Marya; Ly, Justin; Maghames, Rosemary; Montalbetti, Christian A G N; Ortwine, Daniel F; Pérez-Fuertes, Yolanda; Shia, Steven; Stein, Daniel B; Trani, Giancarlo; Vaidya, Darshan G; Wang, Xiaolu; Bromidge, Steven M; Wu, Lawren C; Pei, Zhonghua

    2013-12-01

    Inhibition of the non-receptor tyrosine kinase ITK, a component of the T-cell receptor signalling cascade, may represent a novel treatment for allergic asthma. Here we report the structure-based optimization of a series of benzothiazole amides that demonstrate sub-nanomolar inhibitory potency against ITK with good cellular activity and kinase selectivity. We also elucidate the binding mode of these inhibitors by solving the X-ray crystal structures of several inhibitor-ITK complexes.

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

    SciTech Connect

    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.

    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.

  18. Inhibition of dihydroceramide desaturase activity by the sphingosine kinase inhibitor SKI II.

    PubMed

    Cingolani, Francesca; Casasampere, Mireia; Sanllehí, Pol; Casas, Josefina; Bujons, Jordi; Fabrias, Gemma

    2014-08-01

    Sphingosine kinase inhibitor (SKI) II has been reported as a dual inhibitor of sphingosine kinases (SKs) 1 and 2 and has been extensively used to prove the involvement of SKs and sphingosine-1-phosphate (S1P) in cellular processes. Dihydroceramide desaturase (Des1), the last enzyme in the de novo synthesis of ceramide (Cer), regulates the balance between dihydroceramides (dhCers) and Cers. Both SKs and Des1 have interest as therapeutic targets. Here we show that SKI II is a noncompetitive inhibitor (Ki = 0.3 μM) of Des1 activity with effect also in intact cells without modifying Des1 protein levels. Molecular modeling studies support that the SKI II-induced decrease in Des1 activity could result from inhibition of NADH-cytochrome b5 reductase. SKI II, but not the SK1-specific inhibitor PF-543, provoked a remarkable accumulation of dhCers and their metabolites, while both SKI II and PF-543 reduced S1P to almost undetectable levels. SKI II, but not PF543, reduced cell proliferation with accumulation of cells in the G0/G1 phase. SKI II, but not PF543, induced autophagy. These overall findings should be taken into account when using SKI II as a pharmacological tool, as some of the effects attributed to decreased S1P may actually be caused by augmented dhCers and/or their metabolites.

  19. Synthesis and biological evaluation of analogues of AKT (protein kinase B) inhibitor-IV.

    PubMed

    Sun, Qi; Wu, Runzhi; Cai, Sutang; Lin, Yuan; Sellers, Llewlyn; Sakamoto, Kaori; He, Biao; Peterson, Blake R

    2011-03-10

    Inhibitors of the PI3-kinase/AKT (protein kinase B) pathway are under investigation as anticancer and antiviral agents. The benzimidazole derivative AKT inhibitor-IV (ChemBridge 5233705) affects this pathway and exhibits potent anticancer and antiviral activity. To probe its biological activity, we synthesized AKT inhibitor-IV and 21 analogues using a novel six-step route based on ZrCl(4)-catalyzed cyclization of 1,2-arylenediamines with α,β-unsaturated aldehydes. We examined effects on viability of HeLa carcinoma cells, viability of normal human cells (NHBE), replication of recombinant parainfluenza virus 5 (PIV5) in HeLa cells, and replication of the intracellular bacterium Mycobacterium fortuitum in HeLa cells. Replacement of the benzimidazole N-ethyl substitutent of AKT inhibitor-IV with N-hexyl and N-dodecyl groups enhanced antiviral activity and cytotoxicity against the cancer cell line, but these compounds showed substantially lower toxicity (from 6-fold to >20-fold) against NHBE cells and no effect on M. fortuitum, suggesting inhibition of one or more host protein(s) required for proliferation of cancer cells and PIV5. The key structural elements identified here may facilitate identification of targets of this highly biologically active scaffold.

  20. Small-molecule inhibitors of the receptor tyrosine kinases: promising tools for targeted cancer therapies.

    PubMed

    Hojjat-Farsangi, Mohammad

    2014-08-08

    Chemotherapeutic and cytotoxic drugs are widely used in the treatment of cancer. In spite of the improvements in the life quality of patients, their effectiveness is compromised by several disadvantages. This represents a demand for developing new effective strategies with focusing on tumor cells and minimum side effects. Targeted cancer therapies and personalized medicine have been defined as a new type of emerging treatments. Small molecule inhibitors (SMIs) are among the most effective drugs for targeted cancer therapy. The growing number of approved SMIs of receptor tyrosine kinases (RTKs) i.e., tyrosine kinase inhibitors (TKIs) in the clinical oncology imply the increasing attention and application of these therapeutic tools. Most of the current approved RTK-TKIs in preclinical and clinical settings are multi-targeted inhibitors with several side effects. Only a few specific/selective RTK-TKIs have been developed for the treatment of cancer patients. Specific/selective RTK-TKIs have shown less deleterious effects compared to multi-targeted inhibitors. This review intends to highlight the importance of specific/selective TKIs for future development with less side effects and more manageable agents. This article provides an overview of: (1) the characteristics and function of RTKs and TKIs; (2) the recent advances in the improvement of specific/selective RTK-TKIs in preclinical or clinical settings; and (3) emerging RTKs for targeted cancer therapies by TKIs.

  1. Novel small molecule inhibitors of 3-phosphoinositide-dependent kinase-1.

    PubMed

    Feldman, Richard I; Wu, James M; Polokoff, Mark A; Kochanny, Monica J; Dinter, Harald; Zhu, Daguang; Biroc, Sandra L; Alicke, Bruno; Bryant, Judi; Yuan, Shendong; Buckman, Brad O; Lentz, Dao; Ferrer, Mike; Whitlow, Marc; Adler, Marc; Finster, Silke; Chang, Zheng; Arnaiz, Damian O

    2005-05-20

    The phosphoinositide 3-kinase/3-phosphoinositide-dependent kinase 1 (PDK1)/Akt signaling pathway plays a key role in cancer cell growth, survival, and tumor angiogenesis and represents a promising target for anticancer drugs. Here, we describe three potent PDK1 inhibitors, BX-795, BX-912, and BX-320 (IC(50) = 11-30 nm) and their initial biological characterization. The inhibitors blocked PDK1/Akt signaling in tumor cells and inhibited the anchorage-dependent growth of a variety of tumor cell lines in culture or induced apoptosis. A number of cancer cell lines with elevated Akt activity were >30-fold more sensitive to growth inhibition by PDK1 inhibitors in soft agar than on tissue culture plastic, consistent with the cell survival function of the PDK1/Akt signaling pathway, which is particularly important for unattached cells. BX-320 inhibited the growth of LOX melanoma tumors in the lungs of nude mice after injection of tumor cells into the tail vein. The effect of BX-320 on cancer cell growth in vitro and in vivo indicates that PDK1 inhibitors may have clinical utility as anticancer agents.

  2. Evaluating the promiscuous nature of tyrosine kinase inhibitors assessed in A431 epidermoid carcinoma cells by both chemical- and phosphoproteomics.

    PubMed

    Giansanti, Piero; Preisinger, Christian; Huber, Kilian V M; Gridling, Manuela; Superti-Furga, Giulio; Bennett, Keiryn L; Heck, Albert J R

    2014-07-18

    Deregulation of protein tyrosine kinase signaling has been linked to many diseases, most notably cancer. As a consequence, small molecule inhibitors of protein tyrosine kinases may provide powerful strategies for treatment. Following the successful introduction of imatinib in the treatment of chronic myelogenous leukemia, such drugs are also now evaluated for other types of cancer. However, many developed kinase inhibitors are not very target-specific and therefore may induce side effects. The importance of such side effects is certainly cell-proteome dependent. Understanding the all-inclusive action of a tyrosine kinase inhibitor on each individual cell-type entails the identification of potential targets, combined with monitoring the downstream effects revealing the signaling networks involved. Here, we explored a multilevel quantitative mass spectrometry-based proteomic strategy to identify the direct targets and downstream signaling effect of four tyrosine kinase inhibitors (imatinib, dasatinib, bosutinib, and nilotinib) in epidermoid carcinoma cells, as a model system for skin-cancer. More than 25 tyrosine kinases showed affinity to the drugs, with imatinib and nilotinib displaying a high specificity, especially when compared to dasatinib and bosutinib. Consequently, the latter two drugs showed a larger effect on downstream phosphotyrosine signaling. Many of the proteins affected are key regulators in cell adhesion and invasion. Our data represents a multiplexed view on the promiscuous action of certain tyrosine kinase inhibitors that needs to be taking into consideration prior to the application of these drugs in the treatment of different forms of cancer.

  3. Vitamin C is a kinase inhibitor: dehydroascorbic acid inhibits IkappaBalpha kinase beta.

    PubMed

    Cárcamo, Juan M; Pedraza, Alicia; Bórquez-Ojeda, Oriana; Zhang, Bing; Sanchez, Roberto; Golde, David W

    2004-08-01

    Reactive oxygen species (ROS) are key intermediates in cellular signal transduction pathways whose function may be counterbalanced by antioxidants. Acting as an antioxidant, ascorbic acid (AA) donates two electrons and becomes oxidized to dehydroascorbic acid (DHA). We discovered that DHA directly inhibits IkappaBalpha kinase beta (IKKbeta) and IKKalpha enzymatic activity in vitro, whereas AA did not have this effect. When cells were loaded with AA and induced to generate DHA by oxidative stress in cells expressing a constitutive active IKKbeta, NF-kappaB activation was inhibited. Our results identify a dual molecular action of vitamin C in signal transduction and provide a direct linkage between the redox state of vitamin C and NF-kappaB signaling events. AA quenches ROS intermediates involved in the activation of NF-kappaB and is oxidized to DHA, which directly inhibits IKKbeta and IKKalpha enzymatic activity. These findings define a function for vitamin C in signal transduction other than as an antioxidant and mechanistically illuminate how vitamin C down-modulates NF-kappaB signaling.

  4. Evaluation of Improved Glycogen Synthase Kinase-3α Inhibitors in Models of Acute Myeloid Leukemia

    PubMed Central

    Neumann, Theresa; Benajiba, Lina; Göring, Stefan; Stegmaier, Kimberly; Schmidt, Boris

    2016-01-01

    The challenge for Glycogen Synthase Kinase-3 (GSK-3) inhibitor design lies in achieving high selectivity for one isoform over the other. The therapy of certain diseases, such as acute myeloid leukemia (AML) may require α-isoform specific targeting. The scorpion shaped GSK-3 inhibitors developed by our group achieved the highest GSK-3α selectivity reported so far, but suffered from insufficient aqueous solubility. This work presents the solubility-driven optimization of our isoform-selective inhibitors using a scorpion shaped lead. Among 15 novel compounds, compound 27 showed high activity against GSK-3α/β with the highest GSK-3α selectivity reported to date. Compound 27 was profiled for bioavailability and toxicity in a zebrafish embryo phenotype assay. Selective GSK-3α targeting in AML cell lines was achieved with compound 27, resulting in a strong differentiation phenotype and colony formation impairment, confirming the potential of GSK-3α inhibition in AML therapy. PMID:26496242

  5. Implications of promiscuous Pim-1 kinase fragment inhibitor hydrophobic interactions for fragment-based drug design.

    PubMed

    Good, Andrew C; Liu, Jinyu; Hirth, Bradford; Asmussen, Gary; Xiang, Yibin; Biemann, Hans-Peter; Bishop, Kimberly A; Fremgen, Trisha; Fitzgerald, Maria; Gladysheva, Tatiana; Jain, Annuradha; Jancsics, Katherine; Metz, Markus; Papoulis, Andrew; Skerlj, Renato; Stepp, J David; Wei, Ronnie R

    2012-03-22

    We have studied the subtleties of fragment docking and binding using data generated in a Pim-1 kinase inhibitor program. Crystallographic and docking data analyses have been undertaken using inhibitor complexes derived from an in-house surface plasmon resonance (SPR) fragment screen, a virtual needle screen, and a de novo designed fragment inhibitor hybrid. These investigations highlight that fragments that do not fill their binding pocket can exhibit promiscuous hydrophobic interactions due to the lack of steric constraints imposed on them by the boundaries of said pocket. As a result, docking modes that disagree with an observed crystal structure but maintain key crystallographically observed hydrogen bonds still have potential value in ligand design and optimization. This observation runs counter to the lore in fragment-based drug design that all fragment elaboration must be based on the parent crystal structure alone.

  6. Design of inhibitors of thymidylate kinase from Variola virus as new selective drugs against smallpox.

    PubMed

    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.

  7. Small Molecule Kinase Inhibitors for LRRK2 and Their Application to Parkinson's Disease Models

    PubMed Central

    2012-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder. Several single gene mutations have been linked to this disease. Mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) indicate LRRK2 as promising therapeutic target for the treatment of PD. LRRK2 mutations were observed in sporadic as well as familial PD patients and have been investigated intensively. LRRK2 is a large and complex protein, with multiple enzymatic and protein-interaction domains, each of which is effected by mutations. The most common mutation in PD patients is G2019S. Several LRRK2 inhibitors have been reported already, although the crystal structure of LRRK2 has not yet been determined. This review provides a summary of known LRRK2 inhibitors and will discuss recent in vitro and in vivo results of these inhibitors. PMID:22860184

  8. Large-Scale Computational Screening Identifies First in Class Multitarget Inhibitor of EGFR Kinase and BRD4

    PubMed Central

    Allen, Bryce K.; Mehta, Saurabh; Ember, Stewart W. J.; Schonbrunn, Ernst; Ayad, Nagi; Schürer, Stephan C.

    2015-01-01

    Inhibition of cancer-promoting kinases is an established therapeutic strategy for the treatment of many cancers, although resistance to kinase inhibitors is common. One way to overcome resistance is to target orthogonal cancer-promoting pathways. Bromo and Extra-Terminal (BET) domain proteins, which belong to the family of epigenetic readers, have recently emerged as promising therapeutic targets in multiple cancers. The development of multitarget drugs that inhibit kinase and BET proteins therefore may be a promising strategy to overcome tumor resistance and prolong therapeutic efficacy in the clinic. We developed a general computational screening approach to identify novel dual kinase/bromodomain inhibitors from millions of commercially available small molecules. Our method integrated machine learning using big datasets of kinase inhibitors and structure-based drug design. Here we describe the computational methodology, including validation and characterization of our models and their application and integration into a scalable virtual screening pipeline. We screened over 6 million commercially available compounds and selected 24 for testing in BRD4 and EGFR biochemical assays. We identified several novel BRD4 inhibitors, among them a first in class dual EGFR-BRD4 inhibitor. Our studies suggest that this computational screening approach may be broadly applicable for identifying dual kinase/BET inhibitors with potential for treating various cancers. PMID:26596901

  9. Inhibitors of c-Jun N-terminal kinases: JuNK no more?

    PubMed

    Bogoyevitch, Marie A; Arthur, Peter G

    2008-01-01

    The c-Jun N-terminal kinases (JNKs) have been the subject of intense interest since their discovery in the early 1990s. Major research programs have been directed to the screening and/or design of JNK-selective inhibitors and testing their potential as drugs. We begin this review by considering the first commercially-available JNK ATP-competitive inhibitor, SP600125. We focus on recent studies that have evaluated the actions of SP600125 in lung, brain, kidney and liver following exposure to a range of stress insults including ischemia/reperfusion. In many but not all cases, SP600125 administration has proved beneficial. JNK activation can also follow infection, and we next consider recent examples that demonstrate the benefits of SP600125 administration in viral infection. Additional ATP-competitive JNK inhibitors have now been described following high throughput screening of small molecule libraries, but information on their use in biological systems remains limited and thus these inhibitors will require further evaluation. Peptide substrate-competitive ATP-non-competitive inhibitors of JNK have also now been described, and we discuss the recent advances in the use of JNK inhibitory peptides in the treatment of neuronal death, diabetes and viral infection. We conclude by raising a number of questions that should be considered in the quest for JNK-specific inhibitors.

  10. Evolution of resistance to Aurora kinase B inhibitors in leukaemia cells.

    PubMed

    Failes, Timothy W; Mitic, Gorjana; Abdel-Halim, Heba; Po'uha, Sela T; Liu, Marjorie; Hibbs, David E; Kavallaris, Maria

    2012-01-01

    Aurora kinase inhibitors are new mitosis-targeting drugs currently in clinical trials for the treatment of haematological and solid malignancies. However, knowledge of the molecular factors that influence sensitivity and resistance remains limited. Herein, we developed and characterised an in vitro leukaemia model of resistance to the Aurora B inhibitor ZM447439. Human T-cell acute lymphoblastic leukaemia cells, CCRF-CEM, were selected for resistance in 4 µM ZM447439. CEM/AKB4 cells showed no cross-resistance to tubulin-targeted and DNA-damaging agents, but were hypersensitive to an Aurora kinase A inhibitor. Sequencing revealed a mutation in the Aurora B kinase domain corresponding to a G160E amino acid substitution. Molecular modelling of drug binding in Aurora B containing this mutation suggested that resistance is mediated by the glutamate substitution preventing formation of an active drug-binding motif. Progression of resistance in the more highly selected CEM/AKB8 and CEM/AKB16 cells, derived sequentially from CEM/AKB4 in 8 and 16 µM ZM447439 respectively, was mediated by additional defects. These defects were independent of Aurora B and multi-drug resistance pathways and are associated with reduced apoptosis mostly likely due to reduced inhibition of the catalytic activity of aurora kinase B in the presence of drug. Our findings are important in the context of the use of these new targeted agents in treatment regimes against leukaemia and suggest resistance to therapy may arise through multiple independent mechanisms.

  11. Characterization of GSK′963: a structurally distinct, potent and selective inhibitor of RIP1 kinase

    PubMed Central

    Berger, SB; Harris, P; Nagilla, R; Kasparcova, V; Hoffman, S; Swift, B; Dare, L; Schaeffer, M; Capriotti, C; Ouellette, M; King, BW; Wisnoski, D; Cox, J; Reilly, M; Marquis, RW; Bertin, J; Gough, PJ

    2015-01-01

    Necroptosis and signaling regulated by RIP1 kinase activity is emerging as a key driver of inflammation in a variety of disease settings. A significant amount has been learned about how RIP1 regulates necrotic cell death through the use of the RIP1 kinase inhibitor Necrostatin-1 (Nec-1). Nec-1 has been a transformational tool for exploring the function of RIP1 kinase activity; however, its utility is somewhat limited by moderate potency, off-target activity against indoleamine-2,3-dioxygenase (IDO), and poor pharmacokinetic properties. These limitations of Nec-1 have driven an effort to identify next-generation tools to study RIP1 function, and have led to the identification of 7-Cl-O-Nec-1 (Nec-1s), which has improved pharmacokinetic properties and lacks IDO inhibitory activity. Here we describe the characterization of GSK′963, a chiral small-molecule inhibitor of RIP1 kinase that is chemically distinct from both Nec-1 and Nec-1s. GSK′963 is significantly more potent than Nec-1 in both biochemical and cellular assays, inhibiting RIP1-dependent cell death with an IC50 of between 1 and 4 nM in human and murine cells. GSK′963 is >10 000-fold selective for RIP1 over 339 other kinases, lacks measurable activity against IDO and has an inactive enantiomer, GSK′962, which can be used to confirm on-target effects. The increased in vitro potency of GSK′963 also translates in vivo, where GSK′963 provides much greater protection from hypothermia at matched doses to Nec-1, in a model of TNF-induced sterile shock. Together, we believe GSK′963 represents a next-generation tool for examining the function of RIP1 in vitro and in vivo, and should help to clarify our current understanding of the role of RIP1 in contributing to disease pathogenesis. PMID:27551444

  12. ENMD-2076 is an orally active kinase inhibitor with antiangiogenic and antiproliferative mechanisms of action.

    PubMed

    Fletcher, Graham C; Brokx, Richard D; Denny, Trisha A; Hembrough, Todd A; Plum, Stacy M; Fogler, William E; Sidor, Carolyn F; Bray, Mark R

    2011-01-01

    ENMD-2076 is a novel orally active, small molecule kinase inhibitor with a mechanism of action involving several pathways key to tumor growth and survival: angiogenesis, proliferation, and the cell cycle. ENMD-2076 has selective activity against the mitotic kinase Aurora A, as well as kinases involved in angiogenesis (VEGFRs, FGFRs). ENMD-2076 inhibited the growth in vitro of a wide range of human solid tumor and hematopoietic cancer cell lines with IC(50) values ranging from 0.025 to 0.7 μmol/L. ENMD-2076 was also shown to induce regression or complete inhibition of tumor growth in vivo at well-tolerated doses in tumor xenograft models derived from breast, colon, melanoma, leukemia, and multiple myeloma cell lines. Pharmacodynamic experiments in vivo showed that in addition to inhibiting Aurora A, single doses of ENMD-2076 had sustained inhibitory effects on the activation of Flt3 as well as the angiogenic tyrosine kinases, VEGFR2/KDR and FGFR1 and 2. ENMD-2076 was shown to prevent the formation of new blood vessels and regress formed vessels in vivo at doses equivalent to those that gave substantial activity in tumor xenograft models. These results indicate that ENMD-2076 is a well-tolerated, orally active multitarget kinase inhibitor with a unique antiangiogenic/antiproliferative profile and provides strong preclinical support for use as a therapeutic for human cancers. Several phase 1 studies involving ENMD-2076 have been recently completed, and the compound is currently being evaluated in a phase 2 clinical trial in patients with platinum-resistant ovarian cancer.

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

    PubMed

    Thrane, S; Pedersen, A M; Thomsen, M B H; Kirkegaard, T; Rasmussen, B B; Duun-Henriksen, A K; Lænkholm, A V; Bak, M; Lykkesfeldt, A E; Yde, C W

    2015-08-06

    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 tamoxifen- and fulvestrant-resistant cell lines. Our focus was to identify common and distinct molecular mechanisms involved in tamoxifen- and fulvestrant-resistant cell growth. We identified 18 inhibitors, of which the majority was common for both tamoxifen- and fulvestrant-resistant cell lines. Two compounds, WP1130 and JNJ-7706621, exhibiting prominent preferential growth inhibition of antiestrogen-resistant cell lines, were selected for further studies. WP1130, a deubiquitinase inhibitor, induced caspase-mediated cell death in both tamoxifen- and fulvestrant-resistant cell lines by destabilization of the anti-apoptotic protein Mcl-1. Mcl-1 expression was found upregulated in the antiestrogen-resistant cell lines and depletion of Mcl-1 in resistant cells caused decreased viability. JNJ-7706621, a dual Aurora kinase and cyclin-dependent kinase inhibitor, specifically inhibited growth and caused G2 phase cell cycle arrest of the tamoxifen-resistant cell lines. Knockdown studies showed that Aurora kinase A is essential for growth of the tamoxifen-resistant cells and inhibition of Aurora kinase A resensitized tamoxifen-resistant cells to tamoxifen treatment. Preferential growth inhibition by WP1130 and JNJ-7706621 was also found in T47D-derived tamoxifen-resistant cell lines, pointing at Mcl-1 and Aurora kinase A as potential treatment targets. In addition, tumor samples from 244 estrogen receptor-positive breast cancer patients treated with adjuvant tamoxifen showed that higher expression level of Aurora kinase A was significantly associated with shorter disease-free and overall survival, demonstrating the potential of Aurora kinase A as a biomarker for tamoxifen

  14. A Cell Biologist’s Field Guide to Aurora Kinase Inhibitors

    PubMed Central

    de Groot, Christian O.; Hsia, Judy E.; Anzola, John V.; Motamedi, Amir; Yoon, Michelle; Wong, Yao Liang; Jenkins, David; Lee, Hyun J.; Martinez, Mallory B.; Davis, Robert L.; Gahman, Timothy C.; Desai, Arshad; Shiau, Andrew K.

    2015-01-01

    Aurora kinases are essential for cell division and are frequently misregulated in human cancers. Based on their potential as cancer therapeutics, a plethora of small molecule Aurora kinase inhibitors have been developed, with a subset having been adopted as tools in cell biology. Here, we fill a gap in the characterization of Aurora kinase inhibitors by using biochemical and cell-based assays to systematically profile a panel of 10 commercially available compounds with reported selectivity for Aurora A (MLN8054, MLN8237, MK-5108, MK-8745, Genentech Aurora Inhibitor 1), Aurora B (Hesperadin, ZM447439, AZD1152-HQPA, GSK1070916), or Aurora A/B (VX-680). We quantify the in vitro effect of each inhibitor on the activity of Aurora A alone, as well as Aurora A and Aurora B bound to fragments of their activators, TPX2 and INCENP, respectively. We also report kinome profiling results for a subset of these compounds to highlight potential off-target effects. In a cellular context, we demonstrate that immunofluorescence-based detection of LATS2 and histone H3 phospho-epitopes provides a facile and reliable means to assess potency and specificity of Aurora A versus Aurora B inhibition, and that G2 duration measured in a live imaging assay is a specific readout of Aurora A activity. Our analysis also highlights variation between HeLa, U2OS, and hTERT-RPE1 cells that impacts selective Aurora A inhibition. For Aurora B, all four tested compounds exhibit excellent selectivity and do not significantly inhibit Aurora A at effective doses. For Aurora A, MK-5108 and MK-8745 are significantly more selective than the commonly used inhibitors MLN8054 and MLN8237. A crystal structure of an Aurora A/MK-5108 complex that we determined suggests the chemical basis for this higher specificity. Taken together, our quantitative biochemical and cell-based analyses indicate that AZD1152-HQPA and MK-8745 are the best current tools for selectively inhibiting Aurora B and Aurora A, respectively

  15. The discovery of novel 3-(pyrazin-2-yl)-1H-indazoles as potent pan-Pim kinase inhibitors.

    PubMed

    Wang, Hui-Ling; Cee, Victor J; Chavez, Frank; Lanman, Brian A; Reed, Anthony B; Wu, Bin; Guerrero, Nadia; Lipford, J Russell; Sastri, Christine; Winston, Jeff; Andrews, Kristin L; Huang, Xin; Lee, Matthew R; Mohr, Christopher; Xu, Yang; Zhou, Yihong; Tasker, Andrew S

    2015-02-15

    The three Pim kinases are a small family of serine/threonine kinases regulating several signaling pathways that are fundamental to tumorigenesis. As such, the Pim kinases are a very attractive target for pharmacological inhibition in cancer therapy. Herein, we describe our efforts toward the development of a potent, pan-Pim inhibitor. The synthesis and hit-to-lead SAR development from a 3-(pyrazin-2-yl)-1H-indazole derived hit 2 to the identification of a series of potent, pan-Pim inhibitors such as 13o are described.

  16. The structure of human tau-tubulin kinase 1 both in the apo form and in complex with an inhibitor

    PubMed Central

    Kiefer, Susan E.; Chang, ChiehYing J.; Kimura, S. Roy; Gao, Mian; Xie, Dianlin; Zhang, Yaqun; Zhang, Guifen; Gill, Martin B.; Mastalerz, Harold; Thompson, Lorin A.; Cacace, Angela M.; Sheriff, Steven

    2014-01-01

    Tau-tubulin kinase 1 (TTBK1) is a dual-specificity (serine/threonine and tyrosine) kinase belonging to the casein kinase 1 superfamily. TTBK1 is a neuron-specific kinase that regulates tau phosphorylation. Hyperphosphorylation of tau is implicated in the pathogenesis of Alzheimer’s disease. Two kinase-domain constructs of TTBK1 were expressed in a baculovirus-infected insect-cell system and purified. The purified TTBK1 kinase-domain proteins were crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data were collected and the structure of TTBK1 was determined by molecular replacement both as an apo structure and in complex with a kinase inhibitor. PMID:24637750

  17. A high-throughput, nonisotopic, competitive binding assay for kinases using nonselective inhibitor probes (ED-NSIP).

    PubMed

    Vainshtein, Inna; Silveria, Scott; Kaul, Poonam; Rouhani, Riaz; Eglen, Richard M; Wang, John

    2002-12-01

    A novel competitive binding assay for protein kinase inhibitors has been developed for high-throughput screening (HTS). Unlike functional kinase assays, which are based on detection of substrate phosphorylation by the enzyme, this novel method directly measures the binding potency of compounds to the kinase ATP binding site through competition with a conjugated binding probe. The binding interaction is coupled to a signal amplification system based on complementation of beta-galactosidase enzyme fragments, a homogeneous, nonisotopic assay technology platform developed by DiscoveRx Corp. In the present study, staurosporine, a potent, nonselective kinase inhibitor, was chemically conjugated to a small fragment of beta-galactosidase (termed ED-SS). This was used as the binding probe to the kinase ATP binding pocket. The binding potencies of several inhibitors with diverse structures were assessed by displacement of ED-SS from the kinase. The assay format was specifically evaluated with GSK3alpha, an enzyme previously screened in a radioactive kinase assay (i.e., measurement of [(33)P]-gamma-ATP incorporation into the kinase peptide substrate). Under optimized assay conditions, nonconjugated staurosporine inhibited ED-SS binding in a concentration-dependent manner with an apparent potency (IC(50)) of 11 nM, which was similar to the IC(50) value determined in a radioactive assay. Furthermore, 9 kinase inhibitors with diverse structures, previously identified from chemical compound library screening, were screened using the competitive binding assay. The potencies in the binding assay were in very good agreement with those obtained previously in the isotopic functional activity assay. The binding assay was adapted for automated HTS using selected compound libraries in a 384-well microtiter plate format. The HTS assay was observed to be highly robust and reproducible (Z' factors > 0.7) with high interassay precision (R(2) > 0.96). Interference of compounds with the beta

  18. Development of highly potent and selective diaminothiazole inhibitors of cyclin-dependent kinases

    PubMed Central

    Schonbrunn, Ernst; Betzi, Stephane; Alam, Riazul; Martin, Mathew P.; Becker, Andreas; Han, Huijong; Francis, Rawle; Chakrasali, Ramappa; Jakkaraj, Sudhakar; Kazi, Aslamuzzaman; Sebti, Said M.; Cubitt, Christopher L.; Gebhard, Anthony W.; Hazlehurst, Lori A.; Tash, Joseph S.; Georg, Gunda I.

    2013-01-01

    Cyclin-dependent kinases (CDKs) are serine/threonine protein kinases that act as key regulatory elements in cell cycle progression. We describe the development of highly potent diaminothiazole inhibitors of CDK2 (IC50 = 0.0009 – 0.0015 µM) from a single hit compound with weak inhibitory activity (IC50 = 15 µM), discovered by high-throughput screening. Structure-based design was performed using 35 co-crystal structures of CDK2 liganded with distinct analogues of the parent compound. The profiling of compound 51 against a panel of 339 kinases revealed high selectivity for CDKs, with preference for CDK2 and CDK5 over CDK9, CDK1, CDK4 and CDK6. Compound 51 inhibited the proliferation of 13 out of 15 cancer cell lines with IC50 values between 0.27 and 6.9 µM, which correlated with the complete suppression of retinoblastoma phosphorylation and the onset of apoptosis. Combined, the results demonstrate the potential of this new inhibitors series for further development into CDK-specific chemical probes or therapeutics. PMID:23600925

  19. Discovery of Mer kinase inhibitors by Virtual Screening using Structural Protein-Ligand Interaction Fingerprints

    PubMed Central

    Da, C.; Stashko, M.; Jayakody, C.; Wang, X.; Janzen, W.; Frye, S.; Kireev, D.

    2015-01-01

    Mer is a receptor tyrosine kinase implicated in acute lymphoblastic leukemia (ALL), the most common malignancy in children. The currently available data provide a rationale for development of Mer kinase inhibitors as cancer therapeutics that can target both cell autologous and immune-modulatory anti-tumor effects. We have previously reported several series of potent Mer inhibitors and the objective of the current report is to identify a chemically dissimilar back-up series that might circumvent potential, but currently unknown, flaws inherent to the lead series. To this end, we virtually screened a database of ∼3.8 million commercially available compounds using high-throughput docking followed by a filter involving Structural Protein-Ligand Interaction Fingerprints (SPLIF). SPLIF permits a quantitative assessment of whether a docking pose interacts with the protein target similarly to an endogenous or known synthetic ligand, and therefore helps to improve both sensitivity and specificity with respect to the docking score alone. Of the total of 62 experimentally tested compounds, 15 demonstrated reliable dose-dependent responses in the Mer in vitro kinase activity assay with inhibitory potencies ranging from 0.46 μM to 9.9 μM. PMID:25638502

  20. Discovery of Mer specific tyrosine kinase inhibitors for the treatment and prevention of thrombosis.

    PubMed

    Zhang, Weihe; McIver, Andrew L; Stashko, Michael A; DeRyckere, Deborah; Branchford, Brian R; Hunter, Debra; Kireev, Dmitri; Miley, Michael J; Norris-Drouin, Jacqueline; Stewart, Wendy M; Lee, Minjung; Sather, Susan; Zhou, Yingqiu; Di Paola, Jorge A; Machius, Mischa; Janzen, William P; Earp, H Shelton; Graham, Douglas K; Frye, Stephen V; Wang, Xiaodong

    2013-12-12

    The role of Mer kinase in regulating the second phase of platelet activation generates an opportunity to use Mer inhibitors for preventing thrombosis with diminished likelihood for bleeding as compared to current therapies. Toward this end, we have discovered a novel, Mer kinase specific substituted-pyrimidine scaffold using a structure-based drug design and a pseudo ring replacement strategy. The cocrystal structure of Mer with two compounds (7 and 22) possessing distinct activity have been determined. Subsequent SAR studies identified compound 23 (UNC2881) as a lead compound for in vivo evaluation. When applied to live cells, 23 inhibits steady-state Mer kinase phosphorylation with an IC50 value of 22 nM. Treatment with 23 is also sufficient to block EGF-mediated stimulation of a chimeric receptor containing the intracellular domain of Mer fused to the extracellular domain of EGFR. In addition, 23 potently inhibits collagen-induced platelet aggregation, suggesting that this class of inhibitors may have utility for prevention and/or treatment of pathologic thrombosis.

  1. Discovery of Mer kinase inhibitors by virtual screening using Structural Protein-Ligand Interaction Fingerprints.

    PubMed

    Da, C; Stashko, M; Jayakody, C; Wang, X; Janzen, W; Frye, S; Kireev, D

    2015-03-01

    Mer is a receptor tyrosine kinase implicated in acute lymphoblastic leukemia (ALL), the most common malignancy in children. The currently available data provide a rationale for development of Mer kinase inhibitors as cancer therapeutics that can target both cell autologous and immune-modulatory anti-tumor effects. We have previously reported several series of potent Mer inhibitors and the objective of the current report is to identify a chemically dissimilar back-up series that might circumvent potential, but currently unknown, flaws inherent to the lead series. To this end, we virtually screened a database of ∼3.8million commercially available compounds using high-throughput docking followed by a filter involving Structural Protein-Ligand Interaction Fingerprints (SPLIF). SPLIF permits a quantitative assessment of whether a docking pose interacts with the protein target similarly to an endogenous or known synthetic ligand, and therefore helps to improve both sensitivity and specificity with respect to the docking score alone. Of the total of 62 experimentally tested compounds, 15 demonstrated reliable dose-dependent responses in the Mer in vitro kinase activity assay with inhibitory potencies ranging from 0.46μM to 9.9μM.

  2. Discovery of Mer Specific Tyrosine Kinase Inhibitors for the Treatment and Prevention of Thrombosis

    PubMed Central

    Zhang, Weihe; McIver, Andrew L.; Stashko, Michael A.; DeRyckere, Deborah; Branchford, Brian R.; Hunter, Debra; Kireev, Dmitri; Miley, Michael J.; Norris-Drouin, Jacqueline; Stewart, Wendy M.; Lee, Minjung; Sather, Susan; Zhou, Yingqiu; Di Paola, Jorge A.; Machius, Mischa; Janzen, William P.; Earp, H. Shelton; Graham, Douglas K.; Frye, Stephen V.; Wang, Xiaodong

    2014-01-01

    The role of Mer kinase in regulating the second phase of platelet activation generates an opportunity to use Mer inhibitors for preventing thrombosis with diminished likelihood for bleeding as compared to current therapies. Toward this end, we have discovered a novel, Mer kinase specific substituted-pyrimidine scaffold using a structure-based drug design and a pseudo-ring replacement strategy. The co-crystal structure of Mer with two compounds (7 & 22) possessing distinct activity have been determined. Subsequent SAR studies identified compound 23 (UNC2881) as a lead compound for in vivo evaluation. When applied to live cells, 23 inhibits steady-state Mer kinase phosphorylation with an IC50 value of 22 nM. Treatment with 23 is also sufficient to block EGF-mediated stimulation of a chimeric receptor containing the intracellular domain of Mer fused to the extracellular domain of EGFR. In addition, 23 potently inhibits collagen-induced platelet aggregation, suggesting that this class of inhibitors may have utility for prevention and/or treatment of pathologic thrombosis. PMID:24219778

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

    PubMed Central

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

    2016-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.11405.001 PMID:27841748

  4. Discovery, Synthesis and Characterization of an Orally Bioavailable, Brain Penetrant Inhibitor of Mixed Lineage Kinase 3

    PubMed Central

    Goodfellow, Val S.; Loweth, Colin J.; Ravula, Satheesh B.; Wiemann, Torsten; Nguyen, Thong; Xu, Yang; Todd, Daniel E.; Sheppard, David; Pollack, Scott; Polesskaya, Oksana; Marker, Daniel F.; Dewhurst, Stephen; Gelbard, Harris A.

    2014-01-01

    Inhibition of mixed lineage kinase 3 (MLK3) is a potential strategy for treatment of Parkinson’s Disease and HIV-1 Associated Neurocognitive Disorders (HAND), requiring an inhibitor that can achieve significant brain concentration levels. We report here URMC-099 (1) an orally bioavailable (F = 41%), potent (IC50 = 14 nM) MLK3 inhibitor with excellent brain exposure in mouse PK models and minimal interference with key human CYP450 enzymes or hERG channels. The compound inhibits LPS-induced TNFα release in microglial cells, HIV-1 Tat-induced release of cytokines in human monocytes, and up-regulation of phospho-JNK in Tat-injected brains of mice. Compound 1 likely functions in HAND preclinical models by inhibiting multiple kinase pathways, including MLK3 and LRRK2 (IC50 = 11 nM). We compare the kinase specificity and BBB penetration of 1 with CEP-1347 (2). Compound 1 is well tolerated, with excellent in vivo activity in HAND models, and is under investigation for further development. PMID:24044867

  5. Inhibition of formation of filopodia after axotomy by inhibitors of protein tyrosine kinases.

    PubMed

    Goldberg, D J; Wu, D Y

    1995-08-01

    The activity of motile protrusions of the growth cone--filopodia, veils, and lamellipodia--is essential for directed growth of a neuronal process. The regulation of the formation of these protrusions is not well understood. Numerous filopodia and veils or lamellipodia form within minutes of transection of an Aplysia axon in culture, as the initial components of growth cones of regenerating neurites. Axotomy, therefore, provides a robust and reliable protocol for analyzing the formation of these protrusions. We evaluated the involvement of protein phosphorylation in the regulation of protrusive activity. Of the inhibitors of protein kinases assayed, only the inhibitors of protein tyrosine kinases--genistein, lavendustin A, herbimycin A, and erbstatin analogue--suppressed the formation of protrusions, as assessed by high magnification video microscopy. These drugs did not work by preventing resealing of the axon, as evident from visual inspection and by the unimpaired effectiveness of genistein or lavendustin in preventing formation of filopodia when applied after resealing. Inhibition of protein tyrosine kinases not only prevented the formation of actin-based protrusions, but also caused deterioration of the actin network underlying the protrusive area of preexisting growth cones. Consistent with an involvement of protein tyrosine phosphorylation in the generation of protrusive structures, immunocytochemistry revealed that aggregates of phosphotyrosine appeared at the margins of the axon, from which protrusions emerge shortly after axotomy. These results suggest a role for protein tyrosine phosphorylation in the formation and maintenance of actin-based protrusive structures.

  6. FLT3 tyrosine kinase inhibitors in acute myeloid leukemia: clinical implications and limitations

    PubMed Central

    Kayser, Sabine; Levis, Mark J.

    2015-01-01

    Internal tandem duplications of the FMS-like tyrosine kinase 3 (FLT3) gene are one of the most frequent gene mutations in acute myeloid leukemia (AML) and are associated with poor clinical outcome. The remission rate is high with intensive chemotherapy, but most patients eventually relapse. During the last decade, FLT3 mutations have emerged as an attractive target for a molecularly specific treatment strategy. Targeting FLT3 receptor tyrosine kinases in AML has shown encouraging results in the treatment of FLT3 mutated AML, but in most patients responses are incomplete and not sustained. Newer, more specific compounds seem to have a higher potency and selectivity against FLT3. During therapy with FLT3 tyrosine kinase inhibitors (TKIs) the induction of acquired resistance has emerged as a clinical problem. Therefore, optimization of the targeted therapy and potential treatment options to overcome resistance is currently the focus of clinical research. In this review we discuss the use and limitations of TKIs as a therapeutic strategy for the treatment of FLT3 mutated AML, including mechanisms of resistance to TKIs as well as possible novel strategies to improve FLT3 inhibitor therapy. PMID:23631653

  7. Discovery, synthesis, and characterization of an orally bioavailable, brain penetrant inhibitor of mixed lineage kinase 3.

    PubMed

    Goodfellow, Val S; Loweth, Colin J; Ravula, Satheesh B; Wiemann, Torsten; Nguyen, Thong; Xu, Yang; Todd, Daniel E; Sheppard, David; Pollack, Scott; Polesskaya, Oksana; Marker, Daniel F; Dewhurst, Stephen; Gelbard, Harris A

    2013-10-24

    Inhibition of mixed lineage kinase 3 (MLK3) is a potential strategy for treatment of Parkinson's disease and HIV-1 associated neurocognitive disorders (HAND), requiring an inhibitor that can achieve significant brain concentration levels. We report here URMC-099 (1) an orally bioavailable (F = 41%), potent (IC50 = 14 nM) MLK3 inhibitor with excellent brain exposure in mouse PK models and minimal interference with key human CYP450 enzymes or hERG channels. The compound inhibits LPS-induced TNFα release in microglial cells, HIV-1 Tat-induced release of cytokines in human monocytes and up-regulation of phospho-JNK in Tat-injected brains of mice. Compound 1 likely functions in HAND preclinical models by inhibiting multiple kinase pathways, including MLK3 and LRRK2 (IC50 = 11 nM). We compare the kinase specificity and BBB penetration of 1 with CEP-1347 (2). Compound 1 is well tolerated, with excellent in vivo activity in HAND models, and is under investigation for further development.

  8. SD0006: A Potent, Selective and Orally Available Inhibitor of p38 Kinase

    PubMed Central

    Burnette, Barry L.; Selness, Shaun; Devraj, Raj; Jungbluth, Gail; Kurumbail, Ravi; Stillwell, Loreen; Anderson, Gary; Mnich, Stephen; Hirsch, Jeffrey; Compton, Robert; De Ciechi, Pamela; Hope, Heidi; Hepperle, Michael; Keith, Robert H.; Naing, Win; Shieh, Huey; Portanova, Joseph; Zhang, Yan; Zhang, Jian; Leimgruber, Richard M.; Monahan, Joseph

    2009-01-01

    SD0006 is a diarylpyrazole that was prepared as an inhibitor of p38 kinase-α (p38α). In vitro, SD0006 was selective for p38α kinase over 50 other kinases screened (including p38γ and p38δ with modest selectivity over p38β). Crystal structures with p38α show binding at the ATP site with additional residue interactions outside the ATP pocket unique to p38α that can confer advantages over other ATP competitive inhibitors. Direct correlation between inhibition of p38α activity and that of lipopolysaccharide-stimulated TNFα release was established in cellular models and in vivo, including a phase 1 clinical trial. Potency (IC50) for inhibiting tumor necrosis factor-α (TNFα) release, in vitro and in vivo, was <200 nmol/l. In vivo, SD0006 was effective in the rat streptococcal-cell-wall-induced arthritis model, with dramatic protective effects on paw joint integrity and bone density as shown by radiographic analysis. In the murine collagen-induced arthritis model, equivalence was demonstrated to anti-TNFα treatment. SD0006 also demonstrated good oral anti-inflammatory efficacy with excellent cross-species correlation between the rat, cynomolgus monkey, and human. SD0006 suppressed expression of multiple proinflammatory proteins at both the transcriptional and translational levels. These properties suggest SD0006 could provide broader therapeutic efficacy than cytokine-targeted monotherapeutics. PMID:19590255

  9. 3'-Phosphorylated nucleotides are tight binding inhibitors of nucleoside diphosphate kinase activity.

    PubMed

    Schneider, B; Xu, Y W; Janin, J; Véron, M; Deville-Bonne, D

    1998-10-30

    Nucleoside diphosphate (NDP) kinase catalyzes the phosphorylation of ribo- and deoxyribonucleosides diphosphates into triphosphates. NDP kinase is also involved in malignant tumors and was shown to activate in vitro transcription of the c-myc oncogene by binding to its NHE sequence. The structure of the complex of NDP kinase with bound ADP shows that the nucleotide adopts a different conformation from that observed in other phosphokinases with an internal H bond between the 3'-OH and the beta-O made free by the phosphate transfer. We use intrinsic protein fluorescence to investigate the inhibitory and binding potential of nucleotide analogues phosphorylated in 3'-OH position of the ribose to both wild type and F64W mutant NDP kinase from Dictyostelium discoideum. Due to their 3'-phosphate, 5'-phosphoadenosine 3'-phosphate (PAP) and adenosine 3'-phosphate 5'-phosphosulfate (PAPS) can be regarded as structural analogues of enzyme-bound ADP. The KD of PAPS (10 microM) is three times lower than the KD of ADP. PAPS also acts as a competitive inhibitor toward natural substrates during catalysis, with a KI in agreement with binding data. The crystal structure of the binary complex between Dictyostelium NDP kinase and PAPS was solved at 2.8-A resolution. It shows a new mode of nucleotide binding at the active site with the 3'-phosphate of PAPS located near the catalytic histidine, at the same position as the gamma-phosphate in the transition state. The sulfate group is directed toward the protein surface. PAPS will be useful for the design of high affinity drugs targeted to NDP kinases.

  10. Fragment-based discovery of a dual pan-RET/VEGFR2 kinase inhibitor optimized for single-agent polypharmacology1

    PubMed Central

    Frett, Brendan; Carlomagno, Francesca; Moccia, Maria Luisa; Brescia, Annalisa; Federico, Giorgia; De Falco, Valentina; Admire, Brittany; Chen, Zhongzhu; Qi, Wenqing; Santoro, Massimo; Li, Hong-yu

    2015-01-01

    Oncogenic conversion of the RET (rearranged during transfection) tyrosine kinase is associated with several cancers. A fragment-based chemical screen lead to the identification of a novel RET inhibitor, Pz-1. Modeling and kinetic analysis identified Pz-1 as a Type-II tyrosine kinase inhibitor, able to bind the DFG-out conformation of the kinase. Importantly, from a single-agent polypharmacology standpoint, Pz-1 was shown active on VEGFR2, which can block blood supply required for RET-stimulated growth. In cell based assays, 1.0 nM of Pz-1 strongly inhibited phosphorylation of all tested RET oncoproteins. At 1.0 mg/kg/day per os, Pz-1 abrogated formation of tumors induced by RET-mutant fibroblasts and blocked phosphorylation of both RET and VEGFR2 in tumor tissue. Pz-1 featured no detectable toxicity up to 100.0 mg/kg, which indicated a large therapeutic window. This study validates the effectiveness and usefulness of a medicinal chemistry polypharmacology approach to obtain an inhibitor capable of targeting multiple oncogenic pathways PMID:26126987

  11. Understanding and modulating cyclin-dependent kinase inhibitor specificity: molecular modeling and biochemical evaluation of pyrazolopyrimidinones as CDK2/cyclin A and CDK4/cyclin D1 inhibitors

    NASA Astrophysics Data System (ADS)

    Rossi, Karen A.; Markwalder, Jay A.; Seitz, Steven P.; Chang, Chong-Hwan; Cox, Sarah; Boisclair, Michael D.; Brizuela, Leonardo; Brenner, Stephen L.; Stouten, Pieter F. W.

    2005-02-01<