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Healey E, Stillfried GE, Eckermann S, Dawber JP, Clingan PR, Ranson M. Comparative effectiveness of 5-fluorouracil with and without oxaliplatin in the treatment of colorectal cancer in clinical practice. Anticancer Res 2013; 33:1053-1060. [PMID: 23482781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND First-line chemotherapeutic treatment of colorectal cancer (CRC) typically comprises oral (capecitabine) or intravenous 5-fluorouracil (5-FU) plus leucovorin (LV), in combination with oxaliplatin (XELOX or FOLFOX, respectively), although debate exists regarding the best course of treatment by modality in clinical practice. Evidence from practice comparisons is important in considering the net benefit of alternative chemotherapy regimens, given expected differences in survival associated with compliance and age of patients treated in real life versus controlled trial settings. PATIENTS AND METHODS Practice variation in 5-FU treatment (i.e. 5-FU/leucovorin, FOLFOX, capecitabine and XELOX) of patients with CRC from an Australian area health service (n=636) was analyzed between modalities by patient age, tumour stage and site using non-parametric tests. Survival analyses (n=434) were conducted over a three-year follow-up period using Cox regression, adjusting for observed confounders. RESULTS FOLFOX was the most commonly administered regimen. 5-FU modality was significantly associated with patient age (p<0.001), tumour stage (p<0.001) and site (p<0.001). Cox regression analyses found no significant difference in survival with the addition of oxaliplatin to 5-FU regimens. CONCLUSION Our findings suggested no survival benefit with the addition of oxaliplatin to 5-FU modalities in treating CRC in practice. This raises questions as to the net benefit of oxaliplatin, given its known toxicity profile and expense.
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Kirchmajer DM, Watson CA, Ranson M, Panhuis MIH. Gelapin, a degradable genipin cross-linked gelatin hydrogel. RSC Adv 2013. [DOI: 10.1039/c2ra22859a] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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78
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Dive C, Blackhall F, Hou J, Krebs M, Brady G, Metcalf R, Carter L, Morris K, Rothwell D, Ranson M. 32 Circulating Tumour Cells, Utility Beyond Prognosis? Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71831-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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79
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Vine KL, Indira Chandran V, Locke JM, Matesic L, Lee J, Skropeta D, Bremner JB, Ranson M. Targeting urokinase and the transferrin receptor with novel, anti-mitotic N-alkylisatin cytotoxin conjugates causes selective cancer cell death and reduces tumor growth. Curr Cancer Drug Targets 2012; 12:64-73. [PMID: 22111834 DOI: 10.2174/156800912798888983] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 08/16/2011] [Accepted: 10/13/2011] [Indexed: 11/22/2022]
Abstract
Tumor-specific delivery of ligand-directed prodrugs can increase the therapeutic window of chemotherapeutics by maintaining efficacy whilst decreasing toxic side effects. We have previously described a series of synthetic N-alkylated isatin cytotoxins that destabilize microtubules and induce apoptosis with 10-fold greater potency than conventional anti-mitotics in vitro. Here, we report the characterization, in vitro cytotoxicity and in vivo efficacy of a lead compound, 5,7-dibromo-N-(p-hydroxymethylbenzyl)isatin (N-AI) conjugated via an esterase-labile linker (N-AIE) to two proven targeting ligands, transferrin (Tf) and plasminogen activator inhibitor type 2 (PAI-2/serpinB2). N-AI was released from N-AIE and the targeting ligands Tf/PAI-2 in an esterase-dependent manner at 37 C and both Tf- and PAI-2-N-AIE conjugates were stable at physiological pH. Human cancer cell lines which vary in their expression levels of Tf receptor (TfR/CD71) and PAI-2 target, receptor bound urokinase (uPA) selectively internalized the conjugates. Tf-N-AIE was up to 24 times more active than the free drug and showed clear selectivity patterns based on TfR levels. PAI-2-N-AIE showed equivalent activity compared to the parent drug and strong selectivity patterns for uPA levels. In preliminary in vivo experiments, the PAI-2- and Tf-N-AIE conjugates were efficacious at 1/20(th) and 1/10(th) of the dose of the free N-AI, respectively, in a metastatic, orthotopic human breast tumor xenograft mouse model. Thus, this strategy specifically delivers and concentrates a novel class of isatin-based, tubulin destabilizing agents to tumors in vivo and warrants further detailed preclinical investigation.
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Ranson M, Berghofer P, Vine KL, Greguric I, Shepherd R, Katsifis A. Different radiolabelling methods alter the pharmacokinetic and biodistribution properties of Plasminogen Activator Inhibitor Type 2 (PAI-2) forms. Nucl Med Biol 2012; 39:833-9. [DOI: 10.1016/j.nucmedbio.2012.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/22/2011] [Accepted: 01/17/2012] [Indexed: 11/28/2022]
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Greystoke A, Ranson M. Learning from toxicity patterns in phase I trials during the era of mechanism targeted agents. Ann Oncol 2012; 23:1934-1936. [PMID: 22510374 DOI: 10.1093/annonc/mds116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Ranson M. The plasminogen activation system in pathology: use in prognosis and therapy. Curr Drug Targets 2012; 12:1709-10. [PMID: 21707480 DOI: 10.2174/138945011797635894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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83
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Klinski E, Li S, Zweit J, Hadfield J, Bailey J, Alakhov V, Ranson M. Characterisation of co-polymer targeting of doxorubicin and its iodinated conjugate in tumour models. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.25804401140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hadfield JA, Pietrzynski G, Bailey J, Alakhov V, Sosabowski JK, Zweit J, Ranson M. Preparation of an I-124 labelled doxorubicin conjugate for in vivo assessment of polymer targeted anticancer therapy. J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.25804401130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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85
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Indira Chandran V, Matesic L, Locke JM, Skropeta D, Ranson M, Vine KL. Anti-cancer activity of an acid-labile N-alkylisatin conjugate targeting the transferrin receptor. Cancer Lett 2012; 316:151-6. [DOI: 10.1016/j.canlet.2011.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 09/21/2011] [Accepted: 10/16/2011] [Indexed: 12/18/2022]
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Dean E, Middleton MR, Pwint T, Swaisland H, Carmichael J, Goodege-Kunwar P, Ranson M. Phase I study to assess the safety and tolerability of olaparib in combination with bevacizumab in patients with advanced solid tumours. Br J Cancer 2012; 106:468-74. [PMID: 22223088 PMCID: PMC3273358 DOI: 10.1038/bjc.2011.555] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 11/14/2011] [Accepted: 11/22/2011] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Olaparib (AZD2281) is a potent oral poly(ADP-ribose) polymerase inhibitor with anti-tumour activity and acceptable toxicity as monotherapy in patients with BRCA-deficient cancers. The vascular endothelial growth factor receptor inhibitor bevacizumab has been incorporated into standard of care with chemotherapy in various tumours. This phase I study established the safety, tolerability and clinical pharmacokinetics of olaparib alone and in combination with bevacizumab. METHODS Patients with advanced solid tumours received increasing doses of continuous oral olaparib (100, 200 and 400 mg b.i.d. capsule formulation) in combination with bevacizumab (10 mg kg(-1) intravenous q2w). RESULTS In all, 12 patients enrolled and received treatment. The most common adverse events (AEs) related to olaparib were grade 1/2 nausea and fatigue. No haematological parameters were reported as AEs. No serious AEs related to olaparib or dose-limiting toxicities (DLTs) were reported. Three patients discontinued due to AEs, two patients discontinued both olaparib and bevacizumab and one patient discontinued olaparib. Five patients received combination treatment for over 6 months. There was no evidence that bevacizumab affected olaparib. CONCLUSION The combination of olaparib 400 mg b.i.d. with bevacizumab 10 mg kg(-1) q2w was generally well tolerated with no DLTs. This combination could be considered for future clinical investigation.
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Matthews H, Ranson M, Tyndall JD, Kelso MJ. Synthesis and preliminary evaluation of amiloride analogs as inhibitors of the urokinase-type plasminogen activator (uPA). Bioorg Med Chem Lett 2011; 21:6760-6. [DOI: 10.1016/j.bmcl.2011.09.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/10/2011] [Accepted: 09/13/2011] [Indexed: 10/17/2022]
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Matthews H, Ranson M, Kelso MJ. Anti-tumour/metastasis effects of the potassium-sparing diuretic amiloride: an orally active anti-cancer drug waiting for its call-of-duty? Int J Cancer 2011; 129:2051-61. [PMID: 21544803 DOI: 10.1002/ijc.26156] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 04/14/2011] [Indexed: 12/30/2022]
Abstract
Amiloride.HCl is clinically used as an oral potassium-sparing diuretic, but multiple studies in biochemical, cellular and animal models have shown that the drug also possesses anti-tumour and anti-metastasis activities. The additional effects appear to arise through inhibition of two discrete targets: (i) the sodium-hydrogen exchanger 1 (NHE1), a membrane protein responsible for the characteristically low extracellular pH of tumours and (ii) the urokinase-type plasminogen activator (uPA), a serine protease mediator of cell migration, invasion and metastasis and well-known marker of poor prognosis in cancer. This mini-review summarises for the first time the reported anti-tumour/metastasis effects of amiloride in experimental models, discusses the putative molecular mechanisms responsible for these effects and concludes by commenting on the pros and cons of trialling amiloride or one of its structural analogues as potential new anti-tumour/metastasis drugs.
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Lee JA, Cochran BJ, Lobov S, Ranson M. Forty years later and the role of plasminogen activator inhibitor type 2/SERPINB2 is still an enigma. Semin Thromb Hemost 2011; 37:395-407. [PMID: 21805446 DOI: 10.1055/s-0031-1276589] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Plasminogen activator inhibitor (PAI)-2 expression is acutely upregulated in pregnancy, inflammation, infection, and other pathophysiological conditions. Circumstances that prevent PAI-2 upregulation are associated with chronic pathology. Altogether this strongly suggests that PAI-2 is one of the many proteins that maintain homeostasis during damage or stress. However, several functions ranging from a classical serpin to various intracellular roles have been ascribed to PAI-2 and, because none of these have been definitively proven in vivo, to this day its precise role or roles remains an enigma. This review readdresses the evidence supporting a role for PAI-2 in fibrinolysis and proteolysis within extracellular environments and includes a review of the many potential intracellular functions attributed to PAI-2.
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Cochran BJ, Croucher DR, Lobov S, Saunders DN, Ranson M. Dependence on endocytic receptor binding via a minimal binding motif underlies the differential prognostic profiles of SerpinE1 and SerpinB2 in cancer. J Biol Chem 2011; 286:24467-75. [PMID: 21606492 DOI: 10.1074/jbc.m111.225706] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor overexpression of urokinase-type plasminogen activator (uPA) and its specific inhibitor SerpinE1 (plasminogen activator inhibitor type-1) correlates with poor prognosis and increased metastatic potential. Conversely, tumor expression of uPA and another specific inhibitor, SerpinB2 (plasminogen activator inhibitor type-2), are associated with favorable outcome and relapse-free survival. It is not known how overexpression of these uPA inhibitors results in such disparate outcomes. A possible explanation may be related to the presence of a proposed low density lipoprotein receptor (LDLR)-binding motif in SerpinE1 responsible for mitogenic signaling via ERK that is absent in SerpinB2. We now show that complementation of such a LDLR-binding motif in SerpinB2 by mutagenesis of two key residues enabled high affinity binding to very LDLR (VLDLR). Furthermore, the VLDLR-binding SerpinB2 form behaved in a manner indistinguishable from SerpinE1 in terms of enhanced uPA-SerpinB2 complex endocytosis and subsequent ERK phosphorylation and cell proliferation; that is, the introduction of the LDLR-binding motif to SerpinB2 was necessary and sufficient to allow it to acquire characteristics of SerpinE1 associated with malignancy. In conclusion, this study defines the structural elements underlying the distinct interactions of SerpinE1 versus SerpinB2 with endocytic receptors and how differential VLDLR binding impacts on downstream cellular behavior. This has clear relevance to understanding the paradoxical disease outcomes associated with overexpression of these serpins in cancer.
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Lobov S, Ranson M. Molecular competition between plasminogen activator inhibitors type -1 and -2 for urokinase: Implications for cellular proteolysis and adhesion in cancer. Cancer Lett 2011; 303:118-27. [DOI: 10.1016/j.canlet.2011.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 12/20/2010] [Accepted: 01/19/2011] [Indexed: 10/18/2022]
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92
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Danson SJ, Johnson P, Ward TH, Dawson M, Denneny O, Dickinson G, Aarons L, Watson A, Jowle D, Cummings J, Robson L, Halbert G, Dive C, Ranson M. Phase I pharmacokinetic and pharmacodynamic study of the bioreductive drug RH1. Ann Oncol 2011; 22:1653-1660. [PMID: 21378203 DOI: 10.1093/annonc/mdq638] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND This trial describes a first-in-man evaluation of RH1, a novel bioreductive drug activated by DT-diaphorase (DTD), an enzyme overexpressed in many tumours. PATIENTS AND METHODS A dose-escalation phase I trial of RH1 was carried out. The primary objective was to establish the maximum tolerated dose (MTD) of RH1. Secondary objectives were assessment of toxicity, pharmacokinetic determination of RH1 and pharmacodynamic assessment of drug effect through measurement of DNA cross linking in peripheral blood mononuclear cells (PBMCs) and tumour, DTD activity in tumour and NAD(P)H:quinone oxidoreductase 1 (NQO1) polymorphism status. RESULTS Eighteen patients of World Health Organization performance status of zero to one with advanced refractory solid malignancies were enrolled. MTD was 1430 μg/m(2)/day with reversible bone marrow suppression being dose limiting. Plasma pharmacokinetic analysis showed RH1 is rapidly cleared from blood (t(1/2) = 12.3 min), with AUC increasing proportionately with dose. The comet-X assay demonstrated dose-related increases in DNA cross linking in PBMCs. DNA cross linking was demonstrated in tumours, even with low levels of DTD. Only one patient was homozygous for NQO1 polymorphism precluding any conclusion of its effect. CONCLUSIONS RH1 was well tolerated with predictable and manageable toxicity. The MTD of 1430 μg/m(2)/day is the dose recommended for phase II trials. The biomarkers of DNA cross linking, DTD activity and NQO1 status have been validated and clinically developed.
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Aung KL, Board RE, Ellison G, Donald E, Ward T, Clack G, Ranson M, Hughes A, Newman W, Dive C. Current status and future potential of somatic mutation testing from circulating free DNA in patients with solid tumours. THE HUGO JOURNAL 2010; 4:11-21. [PMID: 22132062 PMCID: PMC3051045 DOI: 10.1007/s11568-011-9149-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/22/2010] [Accepted: 01/12/2011] [Indexed: 12/31/2022]
Abstract
Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient's cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.
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Ranson M, Reck M, Anthoney A, Hanauske AR, Dean E, Melezinek I, Klingelschmitt G, Kletzl H, Blatter J, Twelves C. Erlotinib in combination with pemetrexed for patients with advanced non-small-cell lung cancer (NSCLC): a phase I dose-finding study. Ann Oncol 2010; 21:2233-2239. [DOI: 10.1093/annonc/mdq246] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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95
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Lee JA, Croucher DR, Ranson M. Differential endocytosis of tissue plasminogen activator by serpins PAI-1 and PAI-2 on human peripheral blood monocytes. Thromb Haemost 2010; 104:1133-42. [PMID: 20838737 DOI: 10.1160/th10-02-0121] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 07/23/2010] [Indexed: 11/05/2022]
Abstract
Generation of the broad spectrum protease plasmin is facilitated by the tissue (t-PA) and urokinase (u-PA) plasminogen activators, within multiple physiological and disease states. Finely tuned control of this proteolytic cascade is exerted by the plasminogen activator inhibitors type-1 (PAI-1/SERPINE1) and 2 (PAI-2/SERPINB2). Expression of this network of activators and inhibitors by cells of myeloid lineage appears to be highly interchangeable between physiological environments, and whilst the role of PAI-1 and PAI-2 in regulating u-PA-dependent functions is well established, the interaction between t-PA and PAI-2 on these cell types is poorly characterised. To this end, we used freshly isolated peripheral blood monocytes (PBM) as a model of a t-PA-dependent cellular environment. We demonstrate that while both PAI-1 and PAI-2 could inhibit surface-bound t-PA and are internalised predominately via low-density-lipoprotein receptor family members, PAI-1 enhanced the endocytosis of t-PA, whereas PAI-2 did not. Surface plasmon resonance analyses revealed differential binding affinities between the very-low-density-lipoprotein receptor and t-PA and t-PA:PAI-1 complexes in addition to those previously described with low-density-lipoprotein receptor-related protein. Moreover, t-PA:PAI-2 bound to both endocytosis receptors with similar kinetics to t-PA. These differential biochemical interactions between t-PA and the t-PA:PAI complexes may underlie the observed differences in endocytosis mechanisms on the PBMs. This suggests that while PAI-1 and PAI-2 function similarly in the control of cellular plasmin generation by t-PA, they may have disparate effects on the alternative functions of t-PA via modulation of its engagement with endocytosis receptors.
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Felip E, Ranson M, Cedres S, Brewster M, Mcnally V, Venturi M, Passioukov A, Ross G, Galdermans D. Biomarker analyses from a phase l study of pertuzumab combined with erlotinib in patients (pts) with non-small cell lung cancer (NSCLC). J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.7540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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97
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Molife LR, Forster MD, Krebs M, Pwint T, Middleton MR, Kaye SB, McCormack P, Swaisland H, Carmichael J, Ranson M. A phase I study to determine the comparative bioavailability of two different oral formulations of the PARP inhibitor, olaparib (AZD2281), in patients with advanced solid tumors. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.2599] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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98
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Vine KL, Locke JM, Bremner JB, Pyne SG, Ranson M. Selective targeting of 2′-deoxy-5-fluorouridine to urokinase positive malignant cells in vitro. Bioorg Med Chem Lett 2010; 20:2908-11. [DOI: 10.1016/j.bmcl.2010.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/04/2010] [Accepted: 03/05/2010] [Indexed: 10/19/2022]
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Figuera-Losada M, Ranson M, Sanderson-Smith ML, Walker MJ, Castellino FJ, Prorok M. Effects on human plasminogen conformation and activation rate caused by interaction with VEK-30, a peptide derived from the group A streptococcal M-like protein (PAM). BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1342-9. [PMID: 20152941 DOI: 10.1016/j.bbapap.2010.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 01/14/2010] [Accepted: 01/25/2010] [Indexed: 11/18/2022]
Abstract
In vertebrates, fibrinolysis is primarily carried out by the serine protease plasmin (Pm), which is derived from activation of the zymogen precursor, plasminogen (Pg). One of the most distinctive features of Pg/Pm is the presence of five homologous kringle (K) domains. These structural elements possess conserved Lys-binding sites (LBS) that facilitate interactions with substrates, activators, inhibitors and receptors. In human Pg (hPg), K2 displays weak Lys affinity, however the LBS of this domain has been implicated in an atypical interaction with the N-terminal region of a bacterial surface protein known as PAM (Pg-binding group A streptococcal M-like protein). A direct correlation has been established between invasiveness of group A streptococci and their ability to bind Pg. It has been previously demonstrated that a 30-residue internal peptide (VEK-30) from the N-terminal region of PAM competitively inhibits binding of the full-length parent protein to Pg. We have attempted to determine the effects of this ligand-protein interaction on the regulation of Pg zymogen activation and conformation. Our results show minimal effects on the sedimentation velocity coefficients (S degrees (20,w)) of Pg when associated to VEK-30 and a direct relationship between the concentration of VEK-30 or PAM and the activation rate of Pg. These results are in contrast with the major conformational changes elicited by small-molecule activators of Pg, and point towards a novel mechanism of Pg activation that may underlie group A streptococcal (GAS) virulence.
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Ranson M, Shaw H, Wolf J, Hamilton M, McCarthy S, Dean E, Reid A, Judson I. A phase I dose-escalation and bioavailability study of oral and intravenous formulations of erlotinib (Tarceva®, OSI-774) in patients with advanced solid tumors of epithelial origin. Cancer Chemother Pharmacol 2009; 66:53-8. [DOI: 10.1007/s00280-009-1133-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 09/07/2009] [Indexed: 11/29/2022]
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