| 1. |
- Pass, Jesper, et al.
(författare)
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Murine monoclonal antibodies against murine uPA receptor produced in gene-deficient mice: inhibitory effects on receptor-mediated uPA activity in vitro and in vivo
- 2007
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 97:6, s. 1013-1022
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Tidskriftsartikel (refereegranskat)abstract
- Binding of urokinase plasminogen activator (uPA) to its cellular receptor, uPAR, potentiates plasminogen activation and localizes it to the cell surface. Focal plasminogen activation is involved in both normal and pathological tissue remodeling processes including cancer invasion. The interaction between uPA and uPAR therefore represents a potential target for anti-invasive cancer therapy. Inhibitors of the human uPA-uPAR interaction have no effect in the murine system. To enable in-vivo studies in murine cancer models we have now generated murine monoclonal antibodies (mAbs) against murine uPAR (muPAR) by immunizing uPAR-deficient mice with recombinant muPAR and screened for antibodies, which inhibit the muPA-muPAR interaction. Two of the twelve mAbs obtained, mR1 and mR2, interfered with the interaction between muPAR and the amino-terminal fragment of muPA (mATF) when analyzed by surface plasmon resonance. The epitope for mR1 is located on domain I of muPAR, while that of mR2 is on domains (II-III). In cell binding experiments using radiolabelled mATF, the maximal inhibition obtained with mR1 was 85% while that obtained with mR2 was 50%. The IC(50) value for mR1 was 0.67 nM compared to 0.14 nM for mATF. In an assay based on modified anthrax toxins, requiring cell-bound muPA activity for its cytotoxity, an approximately 50% rescue of the cells could be obtained by addition of mR1. Importantly, in-vivo efficacy of mR1 was demonstrated by the ability of mR1 to rescue mice treated with a lethal dose of uPA-activatable anthrax toxins.
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| 2. |
- Tarpgaard, Line S., et al.
(författare)
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Intact and cleaved plasma soluble urokinase receptor in patients with metastatic colorectal cancer treated with oxaliplatin with or without cetuximab
- 2015
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 137:10, s. 2470-2477
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Tidskriftsartikel (refereegranskat)abstract
- Circulating forms of the urokinase plasminogen activator receptor (uPAR) are associated with prognosis in patients with colorectal cancer. Preclinical studies have shown that uPAR can influence the state of phosphorylation and signalling activity of the epidermal growth factor receptor (EGFR) in a ligand-independent manner. The purpose of the study was to evaluate whether plasma soluble intact and cleaved uPAR(I-III) + (II-III) levels could identify a subpopulation of patients with metastatic colorectal cancer (mCRC) where treatment with cetuximab would have a beneficial effect. Plasma samples were available from 453 patients treated in the NORDIC VII study. Patients were randomized between FLOX and FLOX + cetuximab. The levels of uPAR(I-III) 1(II-III) were determined by time-resolved fluorescence immunoassay. We demonstrated that higher baseline plasma uPAR(I-III) 1(II-III) levels were significantly associated with shorter progression-free survival (PFS) (HR51.30, 1.14-1.48, p=0.0001) and overall survival (OS) (HR51.75, 1.52-2.02, p < 0.0001). Multivariate Cox analysis showed that plasma uPAR(I-III) 1(II-III) was an independent biomarker of short OS (HR51.45, 1.20-1.75, p=0.0001). There were no significant interactions between plasma uPAR(I-III) 1(II-III) levels, KRAS mutational status and treatment either PFS (p=0.43) or OS (p=0.095). However, further explorative analyses indicated that patients with low levels of circulating suPAR and a KRAS wild-type tumor have improved effect from treatment with FLOX+cetuximab as compared to patients with KRAS wild-type and high levels of suPAR. These results thus support the preclinical findings and should be further tested in an independent clinical data set.
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