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  1. Article ; Online: Nonclinical assessment of carcinogenic risk and tumor growth enhancement potential of prasugrel, a platelet-inhibiting therapeutic agent.

    Buckley, Lorrene A / Sanbuissho, Atsushi / Starling, James J / Knadler, Mary Pat / Iversen, Philip W / Jakubowski, Joseph A

    International journal of toxicology

    2012  Volume 31, Issue 4, Page(s) 317–325

    Abstract: Prasugrel, a thienopyridine ADP receptor antagonist, is an orally administered prodrug requiring in vivo metabolism to form the active metabolite that irreversibly inhibits platelet activation and aggregation mediated by the P2Y12[sub 12] receptor. A ... ...

    Abstract Prasugrel, a thienopyridine ADP receptor antagonist, is an orally administered prodrug requiring in vivo metabolism to form the active metabolite that irreversibly inhibits platelet activation and aggregation mediated by the P2Y12[sub 12] receptor. A comprehensive nonclinical safety assessment including genotoxicity and carcinogenicity studies supported the chronic use of prasugrel in patients with atherothrombotic disease. In addition, a special assessment of the potential for prasugrel to enhance tumor growth was undertaken to address regulatory concerns relating to increases in human cancers. Prasugrel demonstrated no evidence of genotoxicity and was not oncogenic in a 2-year rat carcinogenicity study. In the 2-year mouse study, an increase in hepatocellular adenomas was considered secondary to enzyme induction and not relevant to human safety. Further, the absence of any increase in common background tumors at any other organ site in either rodent study indicated a lack of tumor promoting activity (apart from the CYP450 induction-related increase in mouse liver tumors). Cell culture studies with 3 human tumor cell lines (lung, colon, prostate) demonstrated that exposure of serum-starved cells to prasugrel's active and major circulating human metabolites does not increase cell proliferation relative to starved cells stimulated to proliferate by addition of 10% FBS. Prasugrel also did not increase tumor growth relative to vehicle controls in nude mice implanted with 3 human tumor cell lines. Thus, traditional genotoxicity and 2-year bioassays as well as specially designed tumor growth enhancement studies in human tumor cell lines and mouse xenograft models clearly demonstrated prasugrel's lack of tumorigenic potential.
    MeSH term(s) Adenoma, Liver Cell/pathology ; Animals ; Blood Platelets/drug effects ; Blood Platelets/metabolism ; Carcinogens/administration & dosage ; Carcinogens/toxicity ; Cell Line, Tumor ; Cell Proliferation/drug effects ; DNA Damage/drug effects ; Drug Evaluation, Preclinical ; Female ; Humans ; Liver Neoplasms/pathology ; Male ; Mice ; Mice, Inbred ICR ; Piperazines/administration & dosage ; Piperazines/adverse effects ; Platelet Aggregation Inhibitors/administration & dosage ; Platelet Aggregation Inhibitors/adverse effects ; Prasugrel Hydrochloride ; Rats ; Rats, Inbred F344 ; Risk Factors ; Thiophenes/administration & dosage ; Thiophenes/adverse effects ; Xenograft Model Antitumor Assays
    Chemical Substances Carcinogens ; Piperazines ; Platelet Aggregation Inhibitors ; Thiophenes ; Prasugrel Hydrochloride (G89JQ59I13)
    Language English
    Publishing date 2012-07
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1379845-5
    ISSN 1092-874X ; 1091-5818
    ISSN (online) 1092-874X
    ISSN 1091-5818
    DOI 10.1177/1091581812445073
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Oncogenic BRAF Deletions That Function as Homodimers and Are Sensitive to Inhibition by RAF Dimer Inhibitor LY3009120.

    Chen, Shih-Hsun / Zhang, Youyan / Van Horn, Robert D / Yin, Tinggui / Buchanan, Sean / Yadav, Vipin / Mochalkin, Igor / Wong, Swee Seong / Yue, Yong Gang / Huber, Lysiane / Conti, Ilaria / Henry, James R / Starling, James J / Plowman, Gregory D / Peng, Sheng-Bin

    Cancer discovery

    2016  Volume 6, Issue 3, Page(s) 300–315

    Abstract: Unlabelled: We have identified previously undiscovered BRAF in-frame deletions near the αC-helix region of the kinase domain in pancreatic, lung, ovarian, and thyroid cancers. These deletions are mutually exclusive with KRAS mutations and occur in 4.21% ...

    Abstract Unlabelled: We have identified previously undiscovered BRAF in-frame deletions near the αC-helix region of the kinase domain in pancreatic, lung, ovarian, and thyroid cancers. These deletions are mutually exclusive with KRAS mutations and occur in 4.21% of KRAS wild-type pancreatic cancer. siRNA knockdown in cells harboring BRAF deletions showed that the MAPK activity and cell growth are BRAF dependent. Structurally, the BRAF deletions are predicted to shorten the β3/αC-helix loop and hinder its flexibility by locking the helix in the active αC-helix-in conformation that favors dimer formation. Expression of L485-P490-deleted BRAF is able to transform NIH/3T3 cells in a BRAF dimer-dependent manner. BRAF homodimer is confirmed to be the dominant RAF dimer by proximity ligation assays in BRAF deletion cells, which are resistant to the BRAF inhibitor vemurafenib and sensitive to LY3009120, a RAF dimer inhibitor. In tumor models with BRAF deletions, LY3009120 has shown tumor growth regression, whereas vemurafenib is inactive.
    Significance: This study discovered oncogenic BRAF deletions with a distinct activation mechanism dependent on the BRAF dimer formation in tumor cells. LY3009120 is active against these cells and represents a potential treatment option for patients with cancer with these BRAF deletions, or other atypical BRAF mutations where BRAF functions as a dimer.
    MeSH term(s) Animals ; Antineoplastic Agents/chemistry ; Antineoplastic Agents/pharmacology ; Cell Line, Tumor ; Cell Transformation, Neoplastic/genetics ; Disease Models, Animal ; Drug Resistance, Neoplasm ; Ectopic Gene Expression ; Gene Deletion ; Gene Expression ; Humans ; MAP Kinase Signaling System ; Mice ; Models, Molecular ; Phenylurea Compounds/pharmacology ; Protein Conformation ; Protein Interaction Domains and Motifs/genetics ; Protein Kinase Inhibitors/chemistry ; Protein Kinase Inhibitors/pharmacology ; Protein Multimerization ; Proto-Oncogene Proteins B-raf/antagonists & inhibitors ; Proto-Oncogene Proteins B-raf/chemistry ; Proto-Oncogene Proteins B-raf/genetics ; Pyrimidines/pharmacology ; Xenograft Model Antitumor Assays
    Chemical Substances Antineoplastic Agents ; LY3009120 ; Phenylurea Compounds ; Protein Kinase Inhibitors ; Pyrimidines ; Proto-Oncogene Proteins B-raf (EC 2.7.11.1)
    Language English
    Publishing date 2016-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2625242-9
    ISSN 2159-8290 ; 2159-8274
    ISSN (online) 2159-8290
    ISSN 2159-8274
    DOI 10.1158/2159-8290.CD-15-0896
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Modulation of P-glycoprotein but not MRP1- or BCRP-mediated drug resistance by LY335979.

    Shepard, Robert L / Cao, Jin / Starling, James J / Dantzig, Anne H

    International journal of cancer

    2003  Volume 103, Issue 1, Page(s) 121–125

    Abstract: Our study examines the ability of LY335979 (Zosuquidar trihydrochloride) to modulate 3 distinct ABC transporters that are mechanisms of drug resistance: P-glycoprotein (Pgp, ABCB1), multidrug resistance associated protein (MRP1, ABCC2) and breast cancer ... ...

    Abstract Our study examines the ability of LY335979 (Zosuquidar trihydrochloride) to modulate 3 distinct ABC transporters that are mechanisms of drug resistance: P-glycoprotein (Pgp, ABCB1), multidrug resistance associated protein (MRP1, ABCC2) and breast cancer resistance protein (BCRP, ABCG2). Pgp-mediated resistance can be modulated by coadministration with the highly potent, selective inhibitor, LY335979. Modulation of resistance by mitoxantrone and vinorelbine, 2 drugs used to treat certain solid tumors, was examined in a 3-day cytotoxicity assay using a panel of HL60 leukemia cell lines or MCF-7 breast cancer transfectants. LY335979, at 0.5 microM, substantially reversed mitoxantrone resistance and fully reversed vinorelbine resistance of Pgp-expressing HL60/Vinc cells. However, LY335979 did not modulate drug resistance in the MRP1-expressing HL60/ADR or drug-sensitive parental HL60 cells. To ascertain if LY335979 modulates BCRP-mediated drug resistance, the sensitivity of 26-fold mitoxantrone resistant, BCRP-transfected MCF-7 cells was evaluated. Addition of 5 microM LY335979, a concentration approximately 100-fold higher than the affinity of Pgp, had little to no effect on the BCRP transfectant. [(125)I]Iodomycin photolabeled Pgp in CEM/VLB(100) membranes and was inhibited by 5 microM LY335979 and GF120918. No photolabeling of MRP or BCRP occurred in H69AR or MCF-7/BCRP membranes, respectively. These results further demonstrate that LY335979 is highly specific for Pgp and does not modulate MRP1- or BCRP-mediated resistance and can be used in combination with mitoxantrone and vinorelbine in tumor cells.
    MeSH term(s) ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters/metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1/metabolism ; Antineoplastic Agents/pharmacology ; Breast Neoplasms/drug therapy ; Breast Neoplasms/metabolism ; Dibenzocycloheptenes/pharmacology ; Doxorubicin/pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Fetal Viability/drug effects ; Humans ; Immunoblotting ; Neoplasm Proteins/metabolism ; Quinolines/pharmacology ; Tumor Cells, Cultured/drug effects ; Tumor Cells, Cultured/metabolism
    Chemical Substances ABCG2 protein, human ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette, Sub-Family B, Member 1 ; Antineoplastic Agents ; Dibenzocycloheptenes ; Neoplasm Proteins ; Quinolines ; Doxorubicin (80168379AG) ; zosuquidar trihydrochloride (813AGY3126)
    Language English
    Publishing date 2003-01-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 218257-9
    ISSN 1097-0215 ; 0020-7136
    ISSN (online) 1097-0215
    ISSN 0020-7136
    DOI 10.1002/ijc.10792
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: The CDK4/6 inhibitor LY2835219 overcomes vemurafenib resistance resulting from MAPK reactivation and cyclin D1 upregulation.

    Yadav, Vipin / Burke, Teresa F / Huber, Lysiane / Van Horn, Robert D / Zhang, Youyan / Buchanan, Sean G / Chan, Edward M / Starling, James J / Beckmann, Richard P / Peng, Sheng-Bin

    Molecular cancer therapeutics

    2014  Volume 13, Issue 10, Page(s) 2253–2263

    Abstract: B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation ... ...

    Abstract B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation of MAPK signaling. Inhibitors of MAPK signaling, including MEK1/2 inhibitor trametinib, failed to show significant clinical benefit in patients with acquired resistance to vemurafenib. Here, we describe that cell lines with acquired resistance to vemurafenib show reactivation of MAPK signaling and upregulation of cyclin D1 and are sensitive to inhibition of LY2835219, a selective inhibitor of cyclin-dependent kinase (CDK) 4/6. LY2835219 was demonstrated to inhibit growth of melanoma A375 tumor xenografts and delay tumor recurrence in combination with vemurafenib. Furthermore, we developed an in vivo vemurafenib-resistant model by continuous administration of vemurafenib in A375 xenografts. Consistently, we found that MAPK is reactivated and cyclin D1 is elevated in vemurafenib-resistant tumors, as well as in the resistant cell lines derived from these tumors. Importantly, LY2835219 exhibited tumor growth regression in a vemurafenib-resistant model. Mechanistic analysis revealed that LY2835219 induced apoptotic cell death in a concentration-dependent manner in vemurafenib-resistant cells whereas it primarily mediated cell-cycle G1 arrest in the parental cells. Similarly, RNAi-mediated knockdown of cyclin D1 induced significantly higher rate of apoptosis in the resistant cells than in parental cells, suggesting that elevated cyclin D1 activity is important for the survival of vemurafenib-resistant cells. Altogether, we propose that targeting cyclin D1-CDK4/6 signaling by LY2835219 is an effective strategy to overcome MAPK-mediated resistance to B-RAF inhibitors in B-RAF V600E melanoma.
    MeSH term(s) Aminopyridines/pharmacology ; Animals ; Apoptosis/drug effects ; Benzimidazoles/pharmacology ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cyclin D1/metabolism ; Cyclin-Dependent Kinase 4/antagonists & inhibitors ; Cyclin-Dependent Kinase 4/metabolism ; Cyclin-Dependent Kinase 6/antagonists & inhibitors ; Cyclin-Dependent Kinase 6/metabolism ; Drug Resistance, Neoplasm ; Female ; Humans ; Indoles/pharmacology ; MAP Kinase Signaling System/drug effects ; Mice ; Mice, Nude ; Protein Kinase Inhibitors/pharmacology ; Signal Transduction/drug effects ; Sulfonamides/pharmacology ; Transfection ; Up-Regulation/drug effects ; Vemurafenib ; Xenograft Model Antitumor Assays
    Chemical Substances Aminopyridines ; Benzimidazoles ; CCND1 protein, human ; Indoles ; Protein Kinase Inhibitors ; Sulfonamides ; Cyclin D1 (136601-57-5) ; Vemurafenib (207SMY3FQT) ; abemaciclib (60UAB198HK) ; CDK4 protein, human (EC 2.7.11.22) ; CDK6 protein, human (EC 2.7.11.22) ; Cyclin-Dependent Kinase 4 (EC 2.7.11.22) ; Cyclin-Dependent Kinase 6 (EC 2.7.11.22)
    Language English
    Publishing date 2014-08-13
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2063563-1
    ISSN 1538-8514 ; 1535-7163
    ISSN (online) 1538-8514
    ISSN 1535-7163
    DOI 10.1158/1535-7163.MCT-14-0257
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Kinetic validation of the use of carboxydichlorofluorescein as a drug surrogate for MRP5-mediated transport.

    Pratt, Susan / Chen, Victor / Perry, William I / Starling, James J / Dantzig, Anne H

    European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences

    2006  Volume 27, Issue 5, Page(s) 524–532

    Abstract: Multidrug resistance protein-5 (MRP5, ABCC5) is a member of the ATP-binding cassette transporter superfamily that effluxes a broad range of natural and xenobiotic compounds such as cyclic GMP, antiviral compounds, and cancer chemotherapeutic agents ... ...

    Abstract Multidrug resistance protein-5 (MRP5, ABCC5) is a member of the ATP-binding cassette transporter superfamily that effluxes a broad range of natural and xenobiotic compounds such as cyclic GMP, antiviral compounds, and cancer chemotherapeutic agents including nucleoside-based drugs, antifolate agents and platinum compounds. In cellular assays, MRP5 transfectants are less fluorescent after incubation with 5-chloromethylfluorescein diacetate (CMFDA). The present study examines the uptake of a close fluorescent analog, carboxydichlorofluorescein (CDCF), and drug substrates into inside-out membrane vesicles prepared from MRP transfected cells. MRP5-mediated uptake of CDCF was ATP-dependent and GSH-independent and possessed a Km of 12 microM and a Vmax of 56 pmol/min/mg prot. Comparison of kinetic parameters with drug substrates such as methotrexate (MTX), pemetrexed (Alimta), and the metabolite of 5-fluorouracil, 5-fluorodeoxyuridine monophosphate (5-FdUMP) (Km values of 0.3-1.3 mM) indicated that MRP5 has a 25-100-fold higher affinity for CDCF than for these drugs and that they share a common transport binding site. In addition, the potency of MRP5 inhibitors such as probenecid, MK571, and the phosphodiesterase 5 inhibitors correlated well between the uptake of CDCF and MTX. A survey of CDCF uptake by other MRPs revealed that MRP2 (ABCC2) also demonstrated ATP-dependent uptake with a Km of 19 microM and Vmax of 95.5 pmol/min/mg prot, while MRP1 (ABCC1) and MRP4 (ABCC4) had little to no uptake. Taken together, these data indicate that CDCF is a useful fluorescent drug surrogate with which to measure ATP-dependent MRP5-mediated transport.
    MeSH term(s) 3',5'-Cyclic-GMP Phosphodiesterases ; Antimetabolites, Antineoplastic/metabolism ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Fluoresceins/metabolism ; Fluorescent Dyes/metabolism ; Glutamates/metabolism ; Guanine/analogs & derivatives ; Guanine/metabolism ; HeLa Cells ; Humans ; Kinetics ; Membrane Transport Proteins/genetics ; Membrane Transport Proteins/metabolism ; Methotrexate/metabolism ; Multidrug Resistance-Associated Proteins/antagonists & inhibitors ; Multidrug Resistance-Associated Proteins/genetics ; Multidrug Resistance-Associated Proteins/metabolism ; Pemetrexed ; Phosphodiesterase Inhibitors/pharmacology ; Phosphoric Diester Hydrolases/metabolism ; Probenecid/pharmacology ; Propionates/pharmacology ; Quinolines/pharmacology ; Reproducibility of Results ; Staining and Labeling/methods ; Transfection
    Chemical Substances ABCC5 protein, human ; Antimetabolites, Antineoplastic ; Fluoresceins ; Fluorescent Dyes ; Glutamates ; Membrane Transport Proteins ; Multidrug Resistance-Associated Proteins ; Phosphodiesterase Inhibitors ; Propionates ; Quinolines ; Pemetrexed (04Q9AIZ7NO) ; 5(6)-carboxy-2',7'-dichlorofluorescein (111843-78-8) ; 5-chloromethylfluorescein (136832-63-8) ; multidrug resistance-associated protein 2 (4AF605U6JN) ; verlukast (5Q9O54P0H7) ; Guanine (5Z93L87A1R) ; Phosphoric Diester Hydrolases (EC 3.1.4.-) ; 3',5'-Cyclic-GMP Phosphodiesterases (EC 3.1.4.35) ; Cyclic Nucleotide Phosphodiesterases, Type 5 (EC 3.1.4.35) ; PDE5A protein, human (EC 3.1.4.35) ; Probenecid (PO572Z7917) ; Methotrexate (YL5FZ2Y5U1)
    Language English
    Publishing date 2006-04
    Publishing country Netherlands
    Document type Comparative Study ; Journal Article
    ZDB-ID 1154366-8
    ISSN 1879-0720 ; 0928-0987
    ISSN (online) 1879-0720
    ISSN 0928-0987
    DOI 10.1016/j.ejps.2005.09.012
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Efficacy of low-dose oral metronomic dosing of the prodrug of gemcitabine, LY2334737, in human tumor xenografts.

    Pratt, Susan E / Durland-Busbice, Sara / Shepard, Robert L / Donoho, Gregory P / Starling, James J / Wickremsinhe, Enaksha R / Perkins, Everett J / Dantzig, Anne H

    Molecular cancer therapeutics

    2013  Volume 12, Issue 4, Page(s) 481–490

    Abstract: LY2334737, an oral prodrug of gemcitabine, is cleaved in vivo, releasing gemcitabine and valproic acid. Oral dosing of mice results in absorption of intact prodrug with slow systemic hydrolysis yielding higher plasma levels of LY2334737 than gemcitabine ... ...

    Abstract LY2334737, an oral prodrug of gemcitabine, is cleaved in vivo, releasing gemcitabine and valproic acid. Oral dosing of mice results in absorption of intact prodrug with slow systemic hydrolysis yielding higher plasma levels of LY2334737 than gemcitabine and prolonged gemcitabine exposure. Antitumor activity was evaluated in human colon and lung tumor xenograft models. The dose response for efficacy was examined using 3 metronomic schedules, once-a-day dosing for 14 doses, every other day for 7 doses, and once a day for 7 doses, 7 days rest, followed by an additional 7 days of once-a-day dosing. These schedules gave significant antitumor activity and were well tolerated. Oral gavage of 6 mg/kg LY2334737 daily for 21 days gave equivalent activity to i.v. 240 mg/kg gemcitabine. HCl administered once a week for 3 weeks to mice bearing a patient mesothelioma tumor PXF 1118 or a non-small cell lung cancer tumor LXFE 937. The LXFE 397 tumor possessed elevated expression of the equilibrative nucleoside transporter-1 (ENT1) important for gemcitabine uptake but not prodrug uptake and responded significantly better to treatment with LY2334737 than gemcitabine (P ≤ 0.001). In 3 colon xenografts, antitumor activity of LY2334737 plus a maximally tolerated dose of capecitabine, an oral prodrug of 5-fluorouracil, was significantly greater than either monotherapy. During treatment, the expression of carboxylesterase 2 (CES2) and concentrative nucleoside transporter-3 was induced in HCT-116 tumors; both are needed for the activity of the prodrugs. Thus, metronomic oral low-dose LY2334737 is efficacious, well tolerated, and easily combined with capecitabine for improved efficacy. Elevated CES2 or ENT1 expression may enhance LY2334737 tumor response.
    MeSH term(s) Administration, Metronomic ; Administration, Oral ; Animals ; Carcinoma, Non-Small-Cell Lung/drug therapy ; Carcinoma, Non-Small-Cell Lung/genetics ; Carcinoma, Non-Small-Cell Lung/pathology ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Deoxycytidine/analogs & derivatives ; Deoxycytidine/chemistry ; Deoxycytidine/pharmacology ; Deoxyuridine/administration & dosage ; Deoxyuridine/analogs & derivatives ; Deoxyuridine/chemistry ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Gene Expression ; HCT116 Cells ; Humans ; Lung Neoplasms/drug therapy ; Lung Neoplasms/genetics ; Lung Neoplasms/pathology ; Mice ; Prodrugs/administration & dosage ; Prodrugs/chemistry ; Valproic Acid/pharmacology ; Xenograft Model Antitumor Assays
    Chemical Substances LY2334737 ; Prodrugs ; Deoxycytidine (0W860991D6) ; Valproic Acid (614OI1Z5WI) ; gemcitabine (B76N6SBZ8R) ; Deoxyuridine (W78I7AY22C)
    Language English
    Publishing date 2013-01-31
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2063563-1
    ISSN 1538-8514 ; 1535-7163
    ISSN (online) 1538-8514
    ISSN 1535-7163
    DOI 10.1158/1535-7163.MCT-12-0654
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Developing and applying a gene functional association network for anti-angiogenic kinase inhibitor activity assessment in an angiogenesis co-culture model.

    Chen, Yuefeng / Wei, Tao / Yan, Lei / Lawrence, Frank / Qian, Hui-Rong / Burkholder, Timothy P / Starling, James J / Yingling, Jonathan M / Shou, Jianyong

    BMC genomics

    2008  Volume 9, Page(s) 264

    Abstract: Background: Tumor angiogenesis is a highly regulated process involving intercellular communication as well as the interactions of multiple downstream signal transduction pathways. Disrupting one or even a few angiogenesis pathways is often insufficient ... ...

    Abstract Background: Tumor angiogenesis is a highly regulated process involving intercellular communication as well as the interactions of multiple downstream signal transduction pathways. Disrupting one or even a few angiogenesis pathways is often insufficient to achieve sustained therapeutic benefits due to the complexity of angiogenesis. Targeting multiple angiogenic pathways has been increasingly recognized as a viable strategy. However, translation of the polypharmacology of a given compound to its antiangiogenic efficacy remains a major technical challenge. Developing a global functional association network among angiogenesis-related genes is much needed to facilitate holistic understanding of angiogenesis and to aid the development of more effective anti-angiogenesis therapeutics.
    Results: We constructed a comprehensive gene functional association network or interactome by transcript profiling an in vitro angiogenesis model, in which human umbilical vein endothelial cells (HUVECs) formed capillary structures when co-cultured with normal human dermal fibroblasts (NHDFs). HUVEC competence and NHDF supportiveness of cord formation were found to be highly cell-passage dependent. An enrichment test of Biological Processes (BP) of differentially expressed genes (DEG) revealed that angiogenesis related BP categories significantly changed with cell passages. Built upon 2012 DEGs identified from two microarray studies, the resulting interactome captured 17226 functional gene associations and displayed characteristics of a scale-free network. The interactome includes the involvement of oncogenes and tumor suppressor genes in angiogenesis. We developed a network walking algorithm to extract connectivity information from the interactome and applied it to simulate the level of network perturbation by three multi-targeted anti-angiogenic kinase inhibitors. Simulated network perturbation correlated with observed anti-angiogenesis activity in a cord formation bioassay.
    Conclusion: We established a comprehensive gene functional association network to model in vitro angiogenesis regulation. The present study provided a proof-of-concept pilot of applying network perturbation analysis to drug phenotypic activity assessment.
    MeSH term(s) Algorithms ; Angiogenesis Inhibitors/pharmacology ; Biological Assay ; Cell Communication/genetics ; Coculture Techniques ; Dermis/cytology ; Endothelial Cells/cytology ; Fibroblasts/cytology ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; Models, Biological ; Neovascularization, Pathologic/drug therapy ; Neovascularization, Pathologic/genetics ; Oligonucleotide Array Sequence Analysis ; Oncogenes ; Phenotype ; Protein Kinase Inhibitors/pharmacology ; Umbilical Veins/cytology
    Chemical Substances Angiogenesis Inhibitors ; Protein Kinase Inhibitors
    Language English
    Publishing date 2008-06-02
    Publishing country England
    Document type Journal Article
    ISSN 1471-2164
    ISSN (online) 1471-2164
    DOI 10.1186/1471-2164-9-264
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  8. Article ; Online: Reactivation of mitogen-activated protein kinase (MAPK) pathway by FGF receptor 3 (FGFR3)/Ras mediates resistance to vemurafenib in human B-RAF V600E mutant melanoma.

    Yadav, Vipin / Zhang, Xiaoyi / Liu, Jiangang / Estrem, Shawn / Li, Shuyu / Gong, Xue-Qian / Buchanan, Sean / Henry, James R / Starling, James J / Peng, Sheng-Bin

    The Journal of biological chemistry

    2012  Volume 287, Issue 33, Page(s) 28087–28098

    Abstract: Oncogenic B-RAF V600E mutation is found in 50% of melanomas and drives MEK/ERK pathway and cancer progression. Recently, a selective B-RAF inhibitor, vemurafenib (PLX4032), received clinical approval for treatment of melanoma with B-RAF V600E mutation. ... ...

    Abstract Oncogenic B-RAF V600E mutation is found in 50% of melanomas and drives MEK/ERK pathway and cancer progression. Recently, a selective B-RAF inhibitor, vemurafenib (PLX4032), received clinical approval for treatment of melanoma with B-RAF V600E mutation. However, patients on vemurafenib eventually develop resistance to the drug and demonstrate tumor progression within an average of 7 months. Recent reports indicated that multiple complex and context-dependent mechanisms may confer resistance to B-RAF inhibition. In the study described herein, we generated B-RAF V600E melanoma cell lines of acquired-resistance to vemurafenib, and investigated the underlying mechanism(s) of resistance. Biochemical analysis revealed that MEK/ERK reactivation through Ras is the key resistance mechanism in these cells. Further analysis of total gene expression by microarray confirmed a significant increase of Ras and RTK gene signatures in the vemurafenib-resistant cells. Mechanistically, we found that the enhanced activation of fibroblast growth factor receptor 3 (FGFR3) is linked to Ras and MAPK activation, therefore conferring vemurafenib resistance. Pharmacological or genetic inhibition of the FGFR3/Ras axis restored the sensitivity of vemurafenib-resistant cells to vemurafenib. Additionally, activation of FGFR3 sufficiently reactivated Ras/MAPK signaling and conferred resistance to vemurafenib in the parental B-RAF V600E melanoma cells. Finally, we demonstrated that vemurafenib-resistant cells maintain their addiction to the MAPK pathway, and inhibition of MEK or pan-RAF activities is an effective therapeutic strategy to overcome acquired-resistance to vemurafenib. Together, we describe a novel FGFR3/Ras mediated mechanism for acquired-resistance to B-RAF inhibition. Our results have implications for the development of new therapeutic strategies to improve the outcome of patients with B-RAF V600E melanoma.
    MeSH term(s) Amino Acid Substitution ; Cell Line, Tumor ; Drug Resistance, Neoplasm/drug effects ; Drug Resistance, Neoplasm/genetics ; Enzyme Activation/drug effects ; Enzyme Activation/genetics ; Humans ; Indoles/pharmacology ; MAP Kinase Signaling System/drug effects ; MAP Kinase Signaling System/genetics ; Melanoma/drug therapy ; Melanoma/enzymology ; Melanoma/genetics ; Mutation, Missense ; Proto-Oncogene Proteins B-raf/metabolism ; Receptor, Fibroblast Growth Factor, Type 3/genetics ; Receptor, Fibroblast Growth Factor, Type 3/metabolism ; Sulfonamides/pharmacology ; Vemurafenib ; ras Proteins/genetics ; ras Proteins/metabolism
    Chemical Substances Indoles ; Sulfonamides ; Vemurafenib (207SMY3FQT) ; FGFR3 protein, human (EC 2.7.10.1) ; Receptor, Fibroblast Growth Factor, Type 3 (EC 2.7.10.1) ; BRAF protein, human (EC 2.7.11.1) ; Proto-Oncogene Proteins B-raf (EC 2.7.11.1) ; ras Proteins (EC 3.6.5.2)
    Language English
    Publishing date 2012-06-22
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M112.377218
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Developing and applying a gene functional association network for anti-angiogenic kinase inhibitor activity assessment in an angiogenesis co-culture model

    Starling James J / Burkholder Timothy P / Qian Hui-Rong / Lawrence Frank / Yan Lei / Wei Tao / Chen Yuefeng / Yingling Jonathan M / Shou Jianyong

    BMC Genomics, Vol 9, Iss 1, p

    2008  Volume 264

    Abstract: Abstract Background Tumor angiogenesis is a highly regulated process involving intercellular communication as well as the interactions of multiple downstream signal transduction pathways. Disrupting one or even a few angiogenesis pathways is often ... ...

    Abstract Abstract Background Tumor angiogenesis is a highly regulated process involving intercellular communication as well as the interactions of multiple downstream signal transduction pathways. Disrupting one or even a few angiogenesis pathways is often insufficient to achieve sustained therapeutic benefits due to the complexity of angiogenesis. Targeting multiple angiogenic pathways has been increasingly recognized as a viable strategy. However, translation of the polypharmacology of a given compound to its antiangiogenic efficacy remains a major technical challenge. Developing a global functional association network among angiogenesis-related genes is much needed to facilitate holistic understanding of angiogenesis and to aid the development of more effective anti-angiogenesis therapeutics. Results We constructed a comprehensive gene functional association network or interactome by transcript profiling an in vitro angiogenesis model, in which human umbilical vein endothelial cells (HUVECs) formed capillary structures when co-cultured with normal human dermal fibroblasts (NHDFs). HUVEC competence and NHDF supportiveness of cord formation were found to be highly cell-passage dependent. An enrichment test of Biological Processes (BP) of differentially expressed genes (DEG) revealed that angiogenesis related BP categories significantly changed with cell passages. Built upon 2012 DEGs identified from two microarray studies, the resulting interactome captured 17226 functional gene associations and displayed characteristics of a scale-free network. The interactome includes the involvement of oncogenes and tumor suppressor genes in angiogenesis. We developed a network walking algorithm to extract connectivity information from the interactome and applied it to simulate the level of network perturbation by three multi-targeted anti-angiogenic kinase inhibitors. Simulated network perturbation correlated with observed anti-angiogenesis activity in a cord formation bioassay. Conclusion We established a comprehensive gene functional association network to model in vitro angiogenesis regulation. The present study provided a proof-of-concept pilot of applying network perturbation analysis to drug phenotypic activity assessment.
    Keywords Genetics ; QH426-470 ; Biology (General) ; QH301-705.5 ; Science ; Q ; DOAJ:Genetics ; DOAJ:Biology ; DOAJ:Biology and Life Sciences ; Biotechnology ; TP248.13-248.65
    Subject code 570
    Language English
    Publishing date 2008-06-01T00:00:00Z
    Publisher BioMed Central
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Characterization of LY2228820 dimesylate, a potent and selective inhibitor of p38 MAPK with antitumor activity.

    Campbell, Robert M / Anderson, Bryan D / Brooks, Nathan A / Brooks, Harold B / Chan, Edward M / De Dios, Alfonso / Gilmour, Raymond / Graff, Jeremy R / Jambrina, Enrique / Mader, Mary / McCann, Denis / Na, Songqing / Parsons, Stephen H / Pratt, Susan E / Shih, Chuan / Stancato, Louis F / Starling, James J / Tate, Courtney / Velasco, Juan A /
    Wang, Yong / Ye, Xiang S

    Molecular cancer therapeutics

    2013  Volume 13, Issue 2, Page(s) 364–374

    Abstract: p38α mitogen-activated protein kinase (MAPK) is activated in cancer cells in response to environmental factors, oncogenic stress, radiation, and chemotherapy. p38α MAPK phosphorylates a number of substrates, including MAPKAP-K2 (MK2), and regulates the ... ...

    Abstract p38α mitogen-activated protein kinase (MAPK) is activated in cancer cells in response to environmental factors, oncogenic stress, radiation, and chemotherapy. p38α MAPK phosphorylates a number of substrates, including MAPKAP-K2 (MK2), and regulates the production of cytokines in the tumor microenvironment, such as TNF-α, interleukin-1β (IL-1β), IL-6, and CXCL8 (IL-8). p38α MAPK is highly expressed in human cancers and may play a role in tumor growth, invasion, metastasis, and drug resistance. LY2228820 dimesylate (hereafter LY2228820), a trisubstituted imidazole derivative, is a potent and selective, ATP-competitive inhibitor of the α- and β-isoforms of p38 MAPK in vitro (IC(50) = 5.3 and 3.2 nmol/L, respectively). In cell-based assays, LY2228820 potently and selectively inhibited phosphorylation of MK2 (Thr334) in anisomycin-stimulated HeLa cells (at 9.8 nmol/L by Western blot analysis) and anisomycin-induced mouse RAW264.7 macrophages (IC(50) = 35.3 nmol/L) with no changes in phosphorylation of p38α MAPK, JNK, ERK1/2, c-Jun, ATF2, or c-Myc ≤ 10 μmol/L. LY2228820 also reduced TNF-α secretion by lipopolysaccharide/IFN-γ-stimulated macrophages (IC(50) = 6.3 nmol/L). In mice transplanted with B16-F10 melanoma, tumor phospho-MK2 (p-MK2) was inhibited by LY2228820 in a dose-dependent manner [threshold effective dose (TED)(70) = 11.2 mg/kg]. Significant target inhibition (>40% reduction in p-MK2) was maintained for 4 to 8 hours following a single 10 mg/kg oral dose. LY2228820 produced significant tumor growth delay in multiple in vivo cancer models (melanoma, non-small cell lung cancer, ovarian, glioma, myeloma, breast). In summary, LY2228820 is a p38 MAPK inhibitor, which has been optimized for potency, selectivity, drug-like properties (such as oral bioavailability), and efficacy in animal models of human cancer.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Animals ; Anisomycin/pharmacology ; Binding Sites ; Blotting, Western ; Cell Line ; Cell Line, Tumor ; Cells, Cultured ; Cytokines/metabolism ; Dose-Response Relationship, Drug ; HeLa Cells ; Humans ; Imidazoles/chemistry ; Imidazoles/pharmacology ; Macrophages/drug effects ; Macrophages/metabolism ; Melanoma, Experimental/drug therapy ; Melanoma, Experimental/pathology ; Mice ; Molecular Structure ; Neoplasms/drug therapy ; Neoplasms/genetics ; Neoplasms/metabolism ; Phosphorylation/drug effects ; Pyridines/chemistry ; Pyridines/pharmacology ; RNA Interference ; Treatment Outcome ; Xenograft Model Antitumor Assays ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors ; p38 Mitogen-Activated Protein Kinases/genetics ; p38 Mitogen-Activated Protein Kinases/metabolism
    Chemical Substances Cytokines ; Imidazoles ; Pyridines ; Anisomycin (6C74YM2NGI) ; ralimetinib (73I34XW4HD) ; Adenosine Triphosphate (8L70Q75FXE) ; p38 Mitogen-Activated Protein Kinases (EC 2.7.11.24)
    Language English
    Publishing date 2013-12-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2063563-1
    ISSN 1538-8514 ; 1535-7163
    ISSN (online) 1538-8514
    ISSN 1535-7163
    DOI 10.1158/1535-7163.MCT-13-0513
    Database MEDical Literature Analysis and Retrieval System OnLINE

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