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Napp J, Pardo LA, Hartung F, Tietze LF, Stühmer W, Alves F. In vivo imaging of tumour xenografts with an antibody targeting the potassium channel K v10.1. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:721-733. [PMID: 27444284 PMCID: PMC5045485 DOI: 10.1007/s00249-016-1152-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/24/2016] [Accepted: 07/01/2016] [Indexed: 12/31/2022]
Abstract
The Kv10.1 (Eag1) voltage-gated potassium channel represents a promising molecular target for novel cancer therapies or diagnostic purposes. Physiologically, it is only expressed in the brain, but it was found overexpressed in more than 70 % of tumours of diverse origin. Furthermore, as a plasma membrane protein, it is easily accessible to extracellular interventions. In this study we analysed the feasibility of the anti-Kv10.1 monoclonal antibody mAb62 to target tumour cells in vitro and in vivo and to deliver therapeutics to the tumour. Using time-domain near infrared fluorescence (NIRF) imaging in a subcutaneous MDA-MB-435S tumour model in nude mice, we showed that mAb62-Cy5.5 specifically accumulates at the tumour for at least 1 week in vivo with a maximum intensity at 48 h. Blocking experiments with an excess of unlabelled mAb62 and application of the free Cy5.5 fluorophore demonstrate specific binding to the tumour. Ex vivo NIRF imaging of whole tumours as well as NIRF imaging and microscopy of tumour slices confirmed the accumulation of the mAb62-Cy5.5 in tumours but not in brain tissue. Moreover, mAb62 was conjugated to the prodrug-activating enzyme β-D-galactosidase (β-gal; mAb62-β-gal). The β-gal activity of the mAb62-β-gal conjugate was analysed in vitro on Kv10.1-expressing MDA-MB-435S cells in comparison to control AsPC-1 cells. We show that the mAb62-β-gal conjugate possesses high β-gal activity when bound to Kv10.1-expressing MDA-MB-435S cells. Moreover, using the β-gal activatable NIRF probe DDAOG, we detected mAb62-β-gal activity in vivo over the tumour area. In summary, we could show that the anti-Kv10.1 antibody is a promising tool for the development of novel concepts of targeted cancer therapy.
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Affiliation(s)
- Joanna Napp
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075, Göttingen, Germany.,Institute of Interventional and Diagnostic Radiology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Department of Haematology and Medical Oncology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Luis A Pardo
- AG Oncophysiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075, Göttingen, Germany
| | - Franziska Hartung
- AG Oncophysiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075, Göttingen, Germany
| | - Lutz F Tietze
- Institute of Organic and Biomolecular Chemistry, University Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Walter Stühmer
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075, Göttingen, Germany
| | - Frauke Alves
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075, Göttingen, Germany. .,Institute of Interventional and Diagnostic Radiology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Department of Haematology and Medical Oncology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
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Mathejczyk JE, Pauli J, Dullin C, Napp J, Tietze LF, Kessler H, Resch-Genger U, Alves F. Spectroscopically Well-Characterized RGD Optical Probe as a Prerequisite for Lifetime-Gated Tumor Imaging. Mol Imaging 2011. [DOI: 10.2310/7290.2011.00018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Labeling of RGD peptides with near-infrared fluorophores yields optical probes for noninvasive imaging of tumors overexpressing αvβ3 integrins. An important prerequisite for optimum detection sensitivity in vivo is strongly absorbing and highly emissive probes with a known fluorescence lifetime. The RGD-Cy5.5 optical probe was derived by coupling Cy5.5 to a cyclic arginine–glycine–aspartic acid–d-phenylalanine–lysine (RGDfK) peptide via an aminohexanoic acid spacer. Spectroscopic properties of the probe were studied in different matrices in comparison to Cy5.5. For in vivo imaging, human glioblastoma cells were subcutaneously implanted into nude mice, and in vivo fluorescence intensity and lifetime were measured. The fluorescence quantum yield and lifetime of Cy5.5 were found to be barely affected on RGD conjugation but dramatically changed in the presence of proteins. By time domain fluorescence imaging, we demonstrated specific binding of RGD-Cy5.5 to glioblastoma xenografts in nude mice. Discrimination of unspecific fluorescence by lifetime-gated analysis further enhanced the detection sensitivity of RGD-Cy5.5-derived signals. We characterized RGD-Cy5.5 as a strongly emissive and stable probe adequate for selective targeting of αvβ3 integrins. The specificity and thus the overall detection sensitivity in vivo were optimized with lifetime gating, based on the previous determination of the probes fluorescence lifetime under application-relevant conditions.
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Affiliation(s)
- Julia Eva Mathejczyk
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Jutta Pauli
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Christian Dullin
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Joanna Napp
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Lutz-F. Tietze
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Horst Kessler
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Ute Resch-Genger
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
| | - Frauke Alves
- From the Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany; Departments of Hematology and Oncology and Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany; BAM Federal Institute for Materials Research and Testing, Berlin, Germany; Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; and Institute for Advanced Study and Center of Integrated Protein Science Munich,
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Kohl T, Lörinczi E, Pardo LA, Stühmer W. Rapid internalization of the oncogenic K+ channel K(V)10.1. PLoS One 2011; 6:e26329. [PMID: 22022602 PMCID: PMC3192180 DOI: 10.1371/journal.pone.0026329] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 09/24/2011] [Indexed: 11/18/2022] Open
Abstract
K(V)10.1 is a mammalian brain voltage-gated potassium channel whose ectopic expression outside of the brain has been proven relevant for tumor biology. Promotion of cancer cell proliferation by K(V)10.1 depends largely on ion flow, but some oncogenic properties remain in the absence of ion permeation. Additionally, K(V)10.1 surface populations are small compared to large intracellular pools. Control of protein turnover within cells is key to both cellular plasticity and homeostasis, and therefore we set out to analyze how endocytic trafficking participates in controlling K(V)10.1 intracellular distribution and life cycle. To follow plasma membrane K(V)10.1 selectively, we generated a modified channel of displaying an extracellular affinity tag for surface labeling by α-bungarotoxin. This modification only minimally affected K(V)10.1 electrophysiological properties. Using a combination of microscopy and biochemistry techniques, we show that K(V)10.1 is constitutively internalized involving at least two distinct pathways of endocytosis and mainly sorted to lysosomes. This occurs at a relatively fast rate. Simultaneously, recycling seems to contribute to maintain basal K(V)10.1 surface levels. Brief K(V)10.1 surface half-life and rapid lysosomal targeting is a relevant factor to be taken into account for potential drug delivery and targeting strategies directed against K(V)10.1 on tumor cells.
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Affiliation(s)
- Tobias Kohl
- Max-Planck-Institute of Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
| | - Eva Lörinczi
- Max-Planck-Institute of Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
| | - Luis A. Pardo
- Max-Planck-Institute of Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
| | - Walter Stühmer
- Max-Planck-Institute of Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
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Napp J, Dullin C, Müller F, Uhland K, Petri JB, van de Locht A, Steinmetzer T, Alves F. Time-domain in vivo near infrared fluorescence imaging for evaluation of matriptase as a potential target for the development of novel, inhibitor-based tumor therapies. Int J Cancer 2010; 127:1958-74. [PMID: 20473895 DOI: 10.1002/ijc.25405] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Proteolytic enzymes expressed on the surface of tumor cells, and thus easily accessible to external interventions, represent useful targets for anticancer and antimetastatic therapies. In our study, we thoroughly evaluated matriptase, a trypsin-like transmembrane serine protease, as potential target for novel inhibitor-based tumor therapies. We applied time-domain near infrared fluorescence (NIRF) imaging to characterize expression and activity of matriptase in vivo in an orthotopic AsPC-1 pancreatic tumor model in nude mice. We show strong and tumor-specific binding of intravenously injected Cy5.5 labeled antimatriptase antibody (MT-Ab*Cy5.5) only to primary AsPC-1 tumors and their metastases over time within living mice, taking into account fluorescence intensities and fluorescence lifetimes of the applied probes. Specific binding of MT-Ab*Cy5.5 to tumor sites was confirmed by ex vivo NIRF imaging of tumor tissue, NIRF microscopy and by coregistration of the in vivo acquired NIRF intensity maps to anatomical structures visualized by flat-panel volume computed tomography (fpVCT) in living mice. Moreover, using an activatable synthetic substrate S*DY-681 we could clearly demonstrate that matriptase is proteolytically active in vitro as well as in vivo in tumor-bearing mice, and that application of synthetic active-site inhibitors having high affinity and selectivity toward matriptase can efficiently inhibit its proteolytic activity for at least 24 hr. We thus successfully applied NIRF imaging in combination with fpVCT to characterize matriptase as a promising molecular target for inhibitor-based cancer therapies.
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Affiliation(s)
- Joanna Napp
- Department of Haematology and Oncology, University Medical Center, Goettingen, Germany.
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Increased plasma colloid osmotic pressure facilitates the uptake of therapeutic macromolecules in a xenograft tumor model. Neoplasia 2009; 11:812-22. [PMID: 19649211 DOI: 10.1593/neo.09662] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 04/20/2009] [Accepted: 05/06/2009] [Indexed: 11/18/2022] Open
Abstract
Elevated tumor interstitial fluid pressure (TIFP) is a characteristic of most solid tumors. Clinically, TIFP may hamper the uptake of chemotherapeutic drugs into the tumor tissue reducing their therapeutic efficacy. In this study, a means of modulating TIFP to increase the flux of macromolecules into tumor tissue is presented, which is based on the rationale that elevated plasma colloid osmotic pressure (COP) pulls water from tumor interstitium lowering the TIFP. Concentrated human serum albumin (20% HSA), used as an agent to enhance COP, reduced the TIFP time-dependently from 8 to 2 mm Hg in human tumor xenograft models bearing A431 epidermoid vulva carcinomas. To evaluate whether this reduction facilitates the uptake of macromolecules, the intratumoral distribution of fluorescently conjugated dextrans (2.5 mg/ml) and cetuximab (2.0 mg/ml) was probed using novel time domain nearinfrared fluorescence imaging. This method permitted discrimination and semiquantification of tumor-accumulated conjugate from background and unspecific probe fluorescence. The coadministration of 20% HSA together with either dextrans or cetuximab was found to lower the TIFP significantly and increase the concentration of the substances within the tumor tissue in comparison to control tumors. Furthermore, combined administration of 20% HSA plus cetuximab reduced the tumor growth significantly in comparison to standard cetuximab treatment. These data demonstrate that increased COP lowers the TIFP within hours and increases the uptake of therapeutic macromolecules into the tumor interstitium leading to reduced tumor growth. This model represents a novel approach to facilitate the delivery of therapeutics into tumor tissue, particularly monoclonal antibodies.
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