1
|
Schlaak L, Weise C, Kuropka B, Weng A. Mutational Analysis of RIP Type I Dianthin-30 Suggests a Role for Arg24 in Endocytosis. Toxins (Basel) 2024; 16:219. [PMID: 38787071 PMCID: PMC11125672 DOI: 10.3390/toxins16050219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Saponin-mediated endosomal escape is a mechanism that increases the cytotoxicity of type I ribosome-inactivating proteins (type I RIPs). In order to actualize their cytotoxicity, type I RIPs must be released into the cytosol after endocytosis. Without release from the endosomes, type I RIPs are largely degraded and cannot exert their cytotoxic effects. Certain triterpene saponins are able to induce the endosomal escape of these type I RIPs, thus increasing their cytotoxicity. However, the molecular mechanism underlying the endosomal escape enhancement of type I RIPs by triterpene saponins has not been fully elucidated. In this report, we investigate the involvement of the basic amino acid residues of dianthin-30, a type I RIP isolated from the plant Dianthus caryophyllus L., in endosomal escape enhancement using alanine scanning. Therefore, we designed 19 alanine mutants of dianthin-30. Each mutant was combined with SO1861, a triterpene saponin isolated from the roots of Saponaria officinalis L., and subjected to a cytotoxicity screening in Neuro-2A cells. Cytotoxic screening revealed that dianthin-30 mutants with lysine substitutions did not impair the endosomal escape enhancement. There was one particular mutant dianthin, Arg24Ala, that exhibited significantly reduced synergistic cytotoxicity in three mammalian cell lines. However, this reduction was not based on an altered interaction with SO1861. It was, rather, due to the impaired endocytosis of dianthin Arg24Ala into the cells.
Collapse
Affiliation(s)
- Louisa Schlaak
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany;
| | - Christoph Weise
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany; (C.W.); (B.K.)
| | - Benno Kuropka
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany; (C.W.); (B.K.)
| | - Alexander Weng
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany;
| |
Collapse
|
2
|
Schulze FJ, Asadian-Birjand M, Pradela M, Niesler N, Nagel G, Fuchs H. A cleavable peptide adapter augments the activity of targeted toxins in combination with the glycosidic endosomal escape enhancer SO1861. BMC Biotechnol 2024; 24:24. [PMID: 38685061 PMCID: PMC11057116 DOI: 10.1186/s12896-024-00854-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 04/22/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Treatment with tumor-targeted toxins attempts to overcome the disadvantages of conventional cancer therapies by directing a drug's cytotoxic effect specifically towards cancer cells. However, success with targeted toxins has been hampered as the constructs commonly remain bound to the outside of the cell or, after receptor-mediated endocytosis, are either transported back to the cell surface or undergo degradation in lysosomes. Hence, solutions to ensure endosomal escape are an urgent need in treatment with targeted toxins. In this work, a molecular adapter that consists of a cell penetrating peptide and two cleavable peptides was inserted into a targeted toxin between the ribosome-inactivating protein dianthin and the epidermal growth factor. Applying cell viability assays, this study examined whether the addition of the adapter further augments the endosomal escape enhancement of the glycosylated triterpenoid SO1861, which has shown up to more than 1000-fold enhancement in the past. RESULTS Introducing the peptide adapter into the targeted toxin led to an about 12-fold enhancement in the cytotoxicity on target cells while SO1861 caused a 430-fold increase. However, the combination of adapter and glycosylated triterpenoid resulted in a more than 4300-fold enhancement and in addition to a 51-fold gain in specificity. CONCLUSIONS Our results demonstrated that the cleavable peptide augments the endosomal escape mediated by glycosylated triterpenoids while maintaining specificity. Thus, the adapter is a promising addition to glycosylated triterpenoids to further increase the efficacy and therapeutic window of targeted toxins.
Collapse
Affiliation(s)
- Finn J Schulze
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Mazdak Asadian-Birjand
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Michael Pradela
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Interfaculty Institute of Biochemistry, University of Tübingen, Auf der Morgenstelle 34, 72076, Tübingen, Germany
| | - Nicole Niesler
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Gregor Nagel
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Hendrik Fuchs
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
| |
Collapse
|
3
|
Fischer A, Masilamani AP, Schultze-Seemann S, Wolf I, Gratzke C, Fuchs H, Wolf P. Synergistic Cytotoxicity of a Toxin Targeting the Epidermal Growth Factor Receptor and the Glycosylated Triterpenoid SO1861 in Prostate Cancer. J Cancer 2023; 14:3039-3049. [PMID: 37859824 PMCID: PMC10583583 DOI: 10.7150/jca.85691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/01/2023] [Indexed: 10/21/2023] Open
Abstract
Treatment of advanced prostate cancer lacks specificity and curative intent. Therefore, the need for new targeted therapeutic approaches is high. In the present study, we generated the new targeted toxin EGF-PE24mutΔREDLK binding to the epidermal growth factor receptor (EGFR) on the surface of prostate cancer cells. It consists of the human epidermal growth factor (EGF) as binding domain and a de-immunized variant of Pseudomonas Exotoxin A (PE), called PE24mutΔREDLK, as toxin domain. The toxin domain contains a deletion of the C-terminal KDEL-like motif REDLK to prevent its transport from sorting endosomes via the KDEL receptor mediated pathway into the cytosol, where it can inhibit cellular protein biosynthesis and induce apoptosis. Indeed, REDLK deletion resulted in a strong decrease in cytotoxicity of the targeted toxin in prostate cancer cells compared to the parental targeted toxin EGF-PE24mut. However, addition of the plant glycosylated triterpenoid SO1861, which is known to mediate the release of biomolecules from endolysosomal compartments into the cytosol, resulted in an up to almost 7,000-fold enhanced synergistic cytotoxicity. Moreover, combination of PE24mutΔREDLK with SO1861 led to a cytotoxicity that was even 16- to 300-fold enhanced compared to that of EGF-PE24mut. Endolysosomal entrapment of the non-toxic targeted toxin EGF-PE24mutΔREDLK followed by activation through enhanced endosomal escape therefore represents a new promising approach for the future treatment of advanced prostate cancer with high efficacy and diminished side effects.
Collapse
Affiliation(s)
- Alexandra Fischer
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anie Priscilla Masilamani
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Susanne Schultze-Seemann
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Isis Wolf
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty for Biology, University of Freiburg, Freiburg, Germany
| | - Christian Gratzke
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hendrik Fuchs
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin; Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry; Berlin, Germany
| | - Philipp Wolf
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
4
|
Masilamani AP, Huber N, Nagl C, Dettmer-Monaco V, Monaco G, Wolf I, Schultze-Seemann S, Taromi S, Gratzke C, Fuchs H, Wolf P. Enhanced cytotoxicity of a Pseudomonas Exotoxin A based immunotoxin against prostate cancer by addition of the endosomal escape enhancer SO1861. Front Pharmacol 2023; 14:1211824. [PMID: 37484018 PMCID: PMC10358361 DOI: 10.3389/fphar.2023.1211824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/27/2023] [Indexed: 07/25/2023] Open
Abstract
Immunotoxins consist of an antibody or antibody fragment that binds to a specific cell surface structure and a cytotoxic domain that kills the cell after cytosolic uptake. Pseudomonas Exotoxin A (PE) based immunotoxins directed against a variety of tumor entities have successfully entered the clinic. PE possesses a KDEL-like motif (REDLK) that enables the toxin to travel from sorting endosomes via the KDEL-receptor pathway to the endoplasmic reticulum (ER), from where it is transported into the cytosol. There, it ADP-ribosylates the eukaryotic elongation factor 2, resulting in ribosome inhibition and finally apoptosis. One major problem of immunotoxins is their lysosomal degradation causing the need for much more immunotoxin molecules than finally required for induction of cell death. The resulting dose limitations and substantially increased side effects require new strategies to achieve improved cytosolic uptake. Here we generated an immunotoxin consisting of a humanized single chain variable fragment (scFv) targeting the prostate specific membrane antigen (PSMA) and the de-immunized PE variant PE24mut. This immunotoxin, hD7-1(VL-VH)-PE24mut, showed high and specific cytotoxicity in PSMA-expressing prostate cancer cells. We deleted the REDLK sequence to prevent transport to the ER and achieve endosomal entrapment. The cytotoxicity of this immunotoxin, hD7-1(VL-VH)-PE24mutΔREDLK, was greatly reduced. To restore activity, we added the endosomal escape enhancer SO1861 and observed an up to 190,000-fold enhanced cytotoxicity corresponding to a 57-fold enhancement compared to the initial immunotoxin with the REDLK sequence. A biodistribution study with different routes of administration clearly showed that the subcutaneous injection of hD7-1(VL-VH)-PE24mutΔREDLK in mice resulted in the highest tumor uptake. Treatment of mice bearing prostate tumors with a combination of hD7-1(VL-VH)-PE24mutΔREDLK plus SO1861 resulted in inhibition of tumor growth and enhanced overall survival compared to the monotherapies. The endosomal entrapment of non-toxic anti-PSMA immunotoxins followed by enhanced endosomal escape by SO1861 provides new therapeutic options in the future management of prostate cancer.
Collapse
Affiliation(s)
- Anie P. Masilamani
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nathalie Huber
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Constanze Nagl
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Viviane Dettmer-Monaco
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Transfusion Medicine and Gene Therapy, Medical Center—University of Freiburg, Freiburg, Germany
- Center for Chronic Immunodeficiency, Medical Center—University of Freiburg, Freiburg, Germany
| | - Gianni Monaco
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Transfusion Medicine and Gene Therapy, Medical Center—University of Freiburg, Freiburg, Germany
- Center for Chronic Immunodeficiency, Medical Center—University of Freiburg, Freiburg, Germany
- Institute of Neuropathology, Medical Center—University of Freiburg, Freiburg, Germany
| | - Isis Wolf
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty for Biology, University of Freiburg, Freiburg, Germany
| | - Susanne Schultze-Seemann
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sanaz Taromi
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Medicine I, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medical and Life Sciences, University Furtwangen, VS-Schwenningen, Germany
| | - Christian Gratzke
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hendrik Fuchs
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Philipp Wolf
- Department of Urology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
5
|
Koczurkiewicz-Adamczyk P, Grabowska K, Karnas E, Piska K, Wnuk D, Klaś K, Galanty A, Wójcik-Pszczoła K, Michalik M, Pękala E, Fuchs H, Podolak I. Saponin Fraction CIL1 from Lysimachia ciliata L. Enhances the Effect of a Targeted Toxin on Cancer Cells. Pharmaceutics 2023; 15:pharmaceutics15051350. [PMID: 37242592 DOI: 10.3390/pharmaceutics15051350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/22/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Saponins are plant metabolites that possess multidirectional biological activities, among these is antitumor potential. The mechanisms of anticancer activity of saponins are very complex and depend on various factors, including the chemical structure of saponins and the type of cell they target. The ability of saponins to enhance the efficacy of various chemotherapeutics has opened new perspectives for using them in combined anticancer chemotherapy. Co-administration of saponins with targeted toxins makes it possible to reduce the dose of the toxin and thus limit the side effects of overall therapy by mediating endosomal escape. Our study indicates that the saponin fraction CIL1 of Lysimachia ciliata L. can improve the efficacy of the EGFR-targeted toxin dianthin (DE). We investigated the effect of cotreatment with CIL1 + DE on cell viability in a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, on proliferation in a crystal violet assay (CV) and on pro-apoptotic activity using Annexin V/7 Actinomycin D (7-AAD) staining and luminescence detection of caspase levels. Cotreatment with CIL1 + DE enhanced the target cell-specific cytotoxicity, as well as the antiproliferative and proapoptotic properties. We found a 2200-fold increase in both the cytotoxic and antiproliferative efficacy of CIL1 + DE against HER14-targeted cells, while the effect on control NIH3T3 off-target cells was less profound (6.9- or 5.4-fold, respectively). Furthermore, we demonstrated that the CIL1 saponin fraction has a satisfactory in vitro safety profile with a lack of cytotoxic and mutagenic potential.
Collapse
Affiliation(s)
- Paulina Koczurkiewicz-Adamczyk
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 13353 Berlin, Germany
| | - Karolina Grabowska
- Department of Pharmacognosy, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Elżbieta Karnas
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Kamil Piska
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Dawid Wnuk
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Katarzyna Klaś
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Agnieszka Galanty
- Department of Pharmacognosy, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Katarzyna Wójcik-Pszczoła
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Marta Michalik
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Elżbieta Pękala
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| | - Hendrik Fuchs
- Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 13353 Berlin, Germany
| | - Irma Podolak
- Department of Pharmacognosy, Faculty of Pharmacy, Jagiellonian University Medical College, 30-688 Kraków, Poland
| |
Collapse
|
6
|
Panjideh H, Niesler N, Weng A, Fuchs H. Improved Therapy of B-Cell Non-Hodgkin Lymphoma by Obinutuzumab-Dianthin Conjugates in Combination with the Endosomal Escape Enhancer SO1861. Toxins (Basel) 2022; 14:toxins14070478. [PMID: 35878216 PMCID: PMC9318199 DOI: 10.3390/toxins14070478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 12/28/2022] Open
Abstract
Immunotoxins do not only bind to cancer-specific receptors to mediate the elimination of tumor cells through the innate immune system, but also increase target cytotoxicity by the intrinsic toxin activity. The plant glycoside SO1861 was previously reported to enhance the endolysosomal escape of antibody-toxin conjugates in non-hematopoietic cells, thus increasing their cytotoxicity manifold. Here we tested this technology for the first time in a lymphoma in vivo model. First, the therapeutic CD20 antibody obinutuzumab was chemically conjugated to the ribosome-inactivating protein dianthin. The cytotoxicity of obinutuzumab-dianthin (ObiDi) was evaluated on human B-lymphocyte Burkitt’s lymphoma Raji cells and compared to human T-cell leukemia off-target Jurkat cells. When tested in combination with SO1861, the cytotoxicity for target cells was 131-fold greater than for off-target cells. In vivo imaging in a xenograft model of B-cell lymphoma in mice revealed that ObiDi/SO1861 efficiently prevents tumor growth (51.4% response rate) compared to the monotherapy with ObiDi (25.9%) and non-conjugated obinutuzumab (20.7%). The reduction of tumor volume and overall survival was also improved. Taken together, our results substantially contribute to the development of a combination therapy with SO1861 as a platform technology to enhance the efficacy of therapeutic antibody-toxin conjugates in lymphoma and leukemia.
Collapse
Affiliation(s)
- Hossein Panjideh
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Augustenburger Platz 1, D-13353 Berlin, Germany; (H.P.); (N.N.)
| | - Nicole Niesler
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Augustenburger Platz 1, D-13353 Berlin, Germany; (H.P.); (N.N.)
| | - Alexander Weng
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Straße 2+4, D-14195 Berlin, Germany;
| | - Hendrik Fuchs
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Augustenburger Platz 1, D-13353 Berlin, Germany; (H.P.); (N.N.)
- Correspondence:
| |
Collapse
|
7
|
The Molecular Bases of the Interaction between a Saponin from the Roots of Gypsophila paniculata L. and Model Lipid Membranes. Int J Mol Sci 2022; 23:ijms23063397. [PMID: 35328818 PMCID: PMC8949875 DOI: 10.3390/ijms23063397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/14/2022] [Accepted: 03/19/2022] [Indexed: 01/27/2023] Open
Abstract
In view of the possible medical applications of saponins, the molecular structure of a GOTCAB saponin from the roots of Gypsophila paniculata L. was determined by NMR. The biological activity of saponins may depend on the interaction with cell membranes. To obtain more insight in the mechanism of membrane-related saponin function, an experimental and theoretical study was conducted. Ternary lipid systems composed of sphingomyelin, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and cholesterol were used as models of mammalian cell membranes. The membrane–saponin interaction was studied experimentally by monitoring surface pressure in the monomolecular films formed at the air–aqueous subphase interface. The behavior of GOTCAB saponin in a water box and model monolayer systems was characterized by molecular dynamics simulations. The results obtained showed that, in the systems used, cholesterol had a decisive effect on the interaction between GOTCAB and phosphocholine or sphingomyelin as well as on its location within the lipid film.
Collapse
|
8
|
Magnetic Nanoparticle-Based Dianthin Targeting for Controlled Drug Release Using the Endosomal Escape Enhancer SO1861. NANOMATERIALS 2021; 11:nano11041057. [PMID: 33924180 PMCID: PMC8074366 DOI: 10.3390/nano11041057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 01/22/2023]
Abstract
Targeted tumor therapy can provide the basis for the inhibition of tumor growth. However, a number of toxin-based therapeutics lack efficacy because of insufficient endosomal escape after being internalized by endocytosis. To address this problem, the potential of glycosylated triterpenoids, such as SO1861, as endosomal escape enhancers (EEE) for superparamagnetic iron oxide nanoparticle (SPION)-based toxin therapy was investigated. Herein, two different SPION-based particle systems were synthesized, each selectively functionalized with either the targeted toxin, dianthin-epidermal growth factor (DiaEGF), or the EEE, SO1861. After applying both particle systems in vitro, an almost 2000-fold enhancement in tumor cell cytotoxicity compared to the monotherapy with SPION-DiaEGF and a 6.7-fold gain in specificity was observed. Thus, the required dose of the formulation was appreciably reduced, and the therapeutic window widened.
Collapse
|
9
|
The Effect of Small Molecule Pharmacological Agents on the Triterpenoid Saponin Induced Endolysosomal Escape of Saporin and a Saporin-Based Immunotoxin in Target Human Lymphoma Cells. Biomedicines 2021; 9:biomedicines9030300. [PMID: 33804080 PMCID: PMC8000476 DOI: 10.3390/biomedicines9030300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/09/2021] [Accepted: 03/12/2021] [Indexed: 12/24/2022] Open
Abstract
Triterpenoid saponins augment the cytotoxicity of saporin based immunotoxins. It is postulated that this results from a saponin-mediated increase in the endolysosomal escape of the toxin to the cytosol, but this remains to be confirmed. To address this issue, we used a number of pharmacological inhibitors of endocytic processes as probes to investigate the role played by saponin in the endolysosomal escape of fluorescently labeled saporin and a saporin based immunotoxin targeted against CD38 on human lymphoma and leukemia cell lines. Endolysosomal escape of the toxin was measured by flow cytometric pulse shape analysis. These results were compared to the effects of the various inhibitors on the saponin-mediated augmentation of toxin and immunotoxin cytotoxicity. Inhibitors of clathrin-mediated endocytosis, micropinocytosis, and endosomal acidification abrogated the saponin-induced increase in the endolysosomal escape of the toxin into the cytosol, suggesting that these processes may be involved in the internalization of saponin to the same endolysosomal vesicle as the toxin. Alternatively, these processes may play a direct role in the mechanism by which saponin promotes toxin escape from the endolysosomal compartment to the cytosol. Correlation with the effects of these inhibitors on the augmentation of cytotoxicity provides additional evidence that endolysosomal escape is involved in driving augmentation.
Collapse
|
10
|
Niesler N, Arndt J, Silberreis K, Fuchs H. Generation of a soluble and stable apoptin-EGF fusion protein, a targeted viral protein applicable for tumor therapy. Protein Expr Purif 2020; 175:105687. [PMID: 32681952 DOI: 10.1016/j.pep.2020.105687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 11/18/2022]
Abstract
A promising candidate for tumor targeted toxins is the chicken anemia-derived protein apoptin that induces tumor-specific apoptosis. It was aimed to design a novel apoptin-based targeted toxin by genetic fusion of apoptin with the tumor-directed ligand epidermal growth factor (EGF) using Escherichia coli as expression host. However, apoptin is highly hydrophobic and tends to form insoluble aggregates. Therefore, three different apoptin-EGF variants were generated. The fusion protein hexa-histidine (His)-apoptin-EGF (HAE) was expressed in E. coli and purified under denaturing conditions due to inclusion bodies. The protein solubility was improved by maltose-binding protein (MBP) or glutathione S-transferase. The protein MBP-apoptin-EGFHis (MAEH) was found favorable as a targeted toxin regarding final yield (4-6 mg/L) and stability. MBP was enzymatically removed using clotting factor Xa, which resulted in low yield and poor separation. MAEH was tested on target and non-target cell lines. The targeted tumor cell line A431 showed significant toxicity with an IC50 of 69.55 nM upon incubation with MAEH while fibroblasts and target receptor-free cells remained unaffected. Here we designed a novel EGF receptor targeting drug with high yield, purity and stability.
Collapse
Affiliation(s)
- Nicole Niesler
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Augustenburger Platz 1, 13353, Berlin, Germany; Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178, Berlin, Germany
| | - Janine Arndt
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Kim Silberreis
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Augustenburger Platz 1, 13353, Berlin, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195, Berlin, Germany
| | - Hendrik Fuchs
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Augustenburger Platz 1, 13353, Berlin, Germany.
| |
Collapse
|
11
|
Cao XW, Wang FJ, Liew OW, Lu YZ, Zhao J. Analysis of Triterpenoid Saponins Reveals Insights into Structural Features Associated with Potent Protein Drug Enhancement Effects. Mol Pharm 2020; 17:683-694. [PMID: 31913047 DOI: 10.1021/acs.molpharmaceut.9b01158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Plant-based saponins are amphipathic glycosides composed of a hydrophobic aglycone backbone covalently bound to one or more hydrophilic sugar moieties. Recently, the endosomal escape activity of triterpenoid saponins has been investigated as a potentially powerful tool for improved cytosolic penetration of protein drugs internalized by endocytic uptake, thereby greatly enhancing their pharmacological effects. However, only a few saponins have been studied, and the paucity in understanding the structure-activity relationship of saponins imposes significant limitations on their applications. To address this knowledge gap, 12 triterpenoid saponins with diverse structural side chains were screened for their utility as endosomolytic agents. These compounds were used in combination with a toxin (MAP30-HBP) comprising a type I ribosome-inactivating protein fused to a cell-penetrating peptide. Suitability of saponins as endosomolytic agents was assessed on the basis of cytotoxicity, endosomal escape promotion, and synergistic effects on toxins. Five saponins showed strong endosomal escape activity, enhancing MAP30-HBP cytotoxicity by more than 106 to 109 folds. These saponins also enhanced the apoptotic effect of MAP30-HBP in a pH-dependent manner. Additionally, growth inhibition of MAP30-HBP-treated SMMC-7721 cells was greater than that of similarly treated HeLa cells, suggesting that saponin-mediated endosomolytic effect is likely to be cell-specific. Furthermore, the structural features and hydrophobicity of the sugar side chains were analyzed to draw correlations with endosomal escape activity and derive predictive rules, thus providing new insights into structure-activity relationships of saponins. This study revealed new saponins that can potentially be exploited as efficient cytosolic delivery reagents for improved therapeutic drug effects.
Collapse
Affiliation(s)
- Xue-Wei Cao
- Department of Applied Biology , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Fu-Jun Wang
- New Drug R&D Center , Zhejiang Fonow Medicine Company, Ltd. , 209 West Hulian Road , Dongyang 322100 , Zhejiang , China.,Shanghai R&D Center for Standardization of Chinese Medicines , 1200 Cailun Road , Shanghai 201203 , China.,Institute of Chinese Materia , Shanghai University of Traditional Chinese Medicine , 1200 Cailun Road , Shanghai 201203 , China
| | - Oi-Wah Liew
- Cardiovascular Research Institute, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System , Centre for Translational Medicine , MD6#08-01, 14 Medical Drive , 117599 , Singapore
| | - Ye-Zhou Lu
- Department of Applied Biology , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Jian Zhao
- Department of Applied Biology , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China.,State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| |
Collapse
|
12
|
Wensley HJ, Johnston DA, Smith WS, Holmes SE, Flavell SU, Flavell DJ. A Flow Cytometric Method to Quantify the Endosomal Escape of a Protein Toxin to the Cytosol of Target Cells. Pharm Res 2019; 37:16. [PMID: 31873810 PMCID: PMC6928089 DOI: 10.1007/s11095-019-2725-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/18/2019] [Indexed: 02/08/2023]
Abstract
Purpose The aim of this work was to develop a quantitative, flow cytometric method for tracking the endolysosomal escape of a fluorescently labelled saporin toxin. Methods Flow cytometric measurements of fluorescent pulse width and height were used to track the endocytic uptake into Daudi cells of a fluorescently labelled saporin toxin and the saporin based immunotoxin, OKT10-SAP. Subsequently, measurement of changes in pulse width were used to investigate the effect of a triterpenoid saponin on the endolysosomal escape of internalised toxin into the cytosol. Live cell confocal microscopy was used to validate the flow cytometry data. Results Increased endolysosomal escape of saporin and OKT10-SAP was observed by confocal microscopy in cells treated with saponin. Fluorescent pulse width measurements were also able to detect and quantify escape more sensitively than confocal microscopy. Saponin induced endolysosomal escape could be abrogated by treatment with chloroquine, an inhibitor of endolysosomal acidification. Chloroquine abrogation of escape was also mirrored by a concomitant abrogation of cytotoxicity. Conclusions Poor endolysosomal escape is often a rate limiting step for the cytosolic delivery of protein toxins and other macromolecules. Pulse width analysis offers a simple method to semi-quantify the endolysosomal escape of this and similar molecules into the cytosol. Electronic supplementary material The online version of this article (10.1007/s11095-019-2725-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Harrison J Wensley
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, SO16 6YD, UK.,Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Wendy S Smith
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Suzanne E Holmes
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Sopsamorn U Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, SO16 6YD, UK.,University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - David J Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, SO16 6YD, UK. .,University of Southampton Faculty of Medicine, Southampton General Hospital, Southampton, SO16 6YD, UK.
| |
Collapse
|
13
|
Dianthin and Its Potential in Targeted Tumor Therapies. Toxins (Basel) 2019; 11:toxins11100592. [PMID: 31614697 PMCID: PMC6832487 DOI: 10.3390/toxins11100592] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/03/2019] [Indexed: 12/26/2022] Open
Abstract
Dianthin enzymes belong to ribosome-inactivating proteins (RIPs) of type 1, i.e., they only consist of a catalytic domain and do not have a cell binding moiety. Dianthin-30 is very similar to saporin-S3 and saporin-S6, two RIPs often used to design targeted toxins for tumor therapy and already tested in some clinical trials. Nevertheless, dianthin enzymes also exhibit differences to saporin with regard to structure, efficacy, toxicity, immunogenicity and production by heterologous expression. Some of the distinctions might make dianthin more suitable for targeted tumor therapies than other RIPs. The present review provides an overview of the history of dianthin discovery and illuminates its structure, function and role in targeted toxins. It further discusses the option to increase the efficacy of dianthin by endosomal escape enhancers.
Collapse
|
14
|
Smith WS, Johnston DA, Holmes SE, Wensley HJ, Flavell SU, Flavell DJ. Augmentation of Saporin-Based Immunotoxins for Human Leukaemia and Lymphoma Cells by Triterpenoid Saponins: The Modifying Effects of Small Molecule Pharmacological Agents. Toxins (Basel) 2019; 11:toxins11020127. [PMID: 30791598 PMCID: PMC6410249 DOI: 10.3390/toxins11020127] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/11/2019] [Accepted: 02/14/2019] [Indexed: 12/22/2022] Open
Abstract
Triterpenoid saponins from Saponinum album (SA) significantly augment the cytotoxicity of saporin-based immunotoxins but the mechanism of augmentation is not fully understood. We investigated the effects of six small molecule pharmacological agents, which interfere with endocytic and other processes, on SA-mediated augmentation of saporin and saporin-based immunotoxins (ITs) directed against CD7, CD19, CD22 and CD38 on human lymphoma and leukaemia cell lines. Inhibition of clathrin-mediated endocytosis or endosomal acidification abolished the SA augmentation of saporin and of all four immunotoxins tested but the cytotoxicity of each IT or saporin alone was largely unaffected. The data support the hypothesis that endocytic processes are involved in the augmentative action of SA for saporin ITs targeted against a range of antigens expressed by leukaemia and lymphoma cells. In addition, the reactive oxygen species (ROS) scavenger tiron reduced the cytotoxicity of BU12-SAP and OKT10-SAP but had no effect on 4KB128-SAP or saporin cytotoxicity. Tiron also had no effect on SA-mediated augmentation of the saporin-based ITs or unconjugated saporin. These results suggest that ROS are not involved in the augmentation of saporin ITs and that ROS induction is target antigen-dependent and not directly due to the cytotoxic action of the toxin moiety.
Collapse
Affiliation(s)
- Wendy S Smith
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton School of Medicine, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - Suzanne E Holmes
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - Harrison J Wensley
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - Sopsamorn U Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - David J Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton SO16 6YD, UK.
| |
Collapse
|
15
|
Kokorin A, Weise C, Sama S, Weng A. A new type 1 ribosome-inactivating protein from the seeds of Gypsophila elegans M.Bieb. PHYTOCHEMISTRY 2019; 157:121-127. [PMID: 30399494 DOI: 10.1016/j.phytochem.2018.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/16/2018] [Accepted: 10/25/2018] [Indexed: 06/08/2023]
Abstract
Ribosome-inactivating proteins (RIPs) are enzymes with N-glycosylase activity that remove adenine bases from the ribosomal RNA. In theory, one single RIP molecule internalized into a cell is sufficient to induce cell death. For this reason, RIPs are of high potential as toxic payload for anti-tumor therapy. A considerable number of RIPs are synthesized by plants that belong to the carnation family (Caryophyllaceae). Prominent examples are the RIPs saporin from Saponaria officinalis L. or dianthin from Dianthus caryophyllus L. In this study, we have isolated and characterized a novel RIP (termed gypsophilin-S) from the tiny seeds of Gypsophila elegans M. Bieb. (Caryophyllaceae). It is noteworthy that this is the first study presenting the complete amino acid sequence of a RIP from a Gypsophila species. Gypsophilin-S was isolated from the defatted seed material following ammonium sulphate precipitation and HPLC-based ion exchange chromatography. Gypsophilin-S-containing fractions were analysed by SDS-PAGE and mass spectrometry. The full amino acid sequence of gypsophilin-S was assembled by MALDI-TOF-MS-MS and PCR. Gypsophilin-S exhibited strong adenine releasing activity and its cytotoxicity in human glioblastoma cells was investigated using an impedance-based real-time assay in comparison with recombinant saporin and dianthin.
Collapse
Affiliation(s)
- Arsenij Kokorin
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Christoph Weise
- Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Simko Sama
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Alexander Weng
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
| |
Collapse
|
16
|
Weng A. A novel adenine-releasing assay for ribosome-inactivating proteins. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1072:300-304. [PMID: 29202361 DOI: 10.1016/j.jchromb.2017.11.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/07/2017] [Accepted: 11/27/2017] [Indexed: 12/25/2022]
Abstract
Ribosome-inactivating proteins (RIPs) are toxic enzymes that are mostly biosynthesized by plants. RIPs are N-glycosidases that cleave an essential adenine molecule from the 28S rRNA. This is followed by the irreversible inhibition of protein synthesis leading to cell death. By fusing RIPs to cancer cell specific targeting ligands RIPs have been utilized for targeted anti-tumor therapy. The anti-tumoral efficiency of such conjugates depends significantly on the N-glycosidase activity of the RIP domain. Different methods have been developed in order to determine the N-glycosidase activity of RIPs and RIP domain containing anti-tumor toxins. However the existing methods are elaborate and include radioassays, HPLC and enzymatic conversion assays. Here, a simple and cost effective N-glycosidase assay is presented, which is based on the direct determination of the released adenine by thin-layer chromatography (TLC) and TLC-densitometry. An adenine based single stranded oligonucleotide is used as substrate. Following TLC development the released adenine is quantified on silica glass plates by UV absorbance at 260nm.
Collapse
Affiliation(s)
- Alexander Weng
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Str 2+4, 14195 Berlin, Germany.
| |
Collapse
|
17
|
Bhargava C, Dürkop H, Zhao X, Weng A, Melzig MF, Fuchs H. Targeted dianthin is a powerful toxin to treat pancreatic carcinoma when applied in combination with the glycosylated triterpene SO1861. Mol Oncol 2017; 11:1527-1543. [PMID: 28755527 PMCID: PMC5664001 DOI: 10.1002/1878-0261.12115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 06/30/2017] [Accepted: 07/18/2017] [Indexed: 12/18/2022] Open
Abstract
Targeted cancer therapy provides the basis for the arrest of tumor growth in aggressive pancreatic carcinoma; however, a number of protein-based targeted toxins lack efficacy due to insufficient endosomal escape after being endocytosed. Therefore, we tested a fusion protein of the ribosome-inactivating protein dianthin and human epidermal growth factor in combination with a glycosylated triterpene (SO1861) that serves as an endosomal escape enhancer. In vitro investigations with the pancreatic carcinoma cell lines BxPC-3 and MIA PaCa-2 revealed no significant differences to off-target cells in the half maximal inhibitory concentration (IC50 ) for the fusion protein. In contrast, combination with SO1861 decreased the IC50 for BxPC-3 cells from 100 to 0.17 nm, whereas control cells remained unaffected. Monotherapy of BxPC-3 xenografts in CD-1 nude mice led to a 51.7% average reduction in tumor size (40.8 mm3 ) when compared to placebo; however, combined treatment with SO1861 resulted in a more than 13-fold better efficacy (3.0 mm3 average tumor size) with complete regression in 80% of cases. Immunohistochemical analyses showed that tumor cells with lower target receptor expression are, in contrast to the combination therapy, able to escape from the monotherapy, which finally results in tumor growth. At the effective concentration, we did not observe liver toxicity and saw no other side effects with the exception of a reversible skin hardening at the SO1861 injection site, alongside an increase in platelet counts, plateletcrit, and platelet distribution width. In conclusion, combining a targeted toxin with SO1861 is proven to be a very promising approach for pancreatic cancer treatment.
Collapse
Affiliation(s)
- Cheenu Bhargava
- Institute for Laboratory MedicineClinical Chemistry and PathobiochemistryCharité – Universitätsmedizin BerlinGermany
| | | | - Xiangli Zhao
- Institute for Laboratory MedicineClinical Chemistry and PathobiochemistryCharité – Universitätsmedizin BerlinGermany
| | - Alexander Weng
- Institute for Laboratory MedicineClinical Chemistry and PathobiochemistryCharité – Universitätsmedizin BerlinGermany
- Institute for PharmacyFreie Universität BerlinGermany
| | | | - Hendrik Fuchs
- Institute for Laboratory MedicineClinical Chemistry and PathobiochemistryCharité – Universitätsmedizin BerlinGermany
| |
Collapse
|
18
|
Zhang JJ, Zhu KQ. A novel antitumor compound nobiliside D isolated from sea cucumber ( Holothuria nobilis Selenka). Exp Ther Med 2017; 14:1653-1658. [PMID: 28810632 DOI: 10.3892/etm.2017.4656] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 11/25/2016] [Indexed: 11/05/2022] Open
Abstract
An anticancer compound, triterpene glycoside, was isolated from Holothuria nobilis Selenka. Its chemical structure and configuration were determined by two-dimensional nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry. The novel active compound was identified as nobiliside D, with the molecular formula C40H61O17SNa and chemical name 3-O-[-β-D-pyranosyl (1-2)-4'-O-sulfon-ate-β-D-xylopyranosyl]-alkoxy-9-ene-3β, 12α, 17α, 25β-4 alcohol. An antitumor test was performed using xCELLigence Real-Time Cell Analysis. Nobiliside D exhibited inhibitory effects on human leukemic cell line K562, human leukemia cell line U937, human lung cancer cell line A-549, human cervix carcinoma cell line HeLa, human breast cancer cell line MCF-7 and human liver carcinoma cell line HepG2. Nobiliside exhibited the greatest inhibitory effect on K562 and MCF-7 cells with an IC50 of 0.83±0.14 and 0.82±0.11 µg/ml, respectively. When human tumor cell lines K562 and MCF-7 were treated by nobiliside D (0.5 µg/ml) for 24 h, 45.8% of K562 cells and 58.7% of MCF-7 cells were apoptotic, whereas only 0.5% of un-treated control cells were apoptotic. These data indicate the compound should offer potential as a novel drug for the treatment of a range of cancers.
Collapse
Affiliation(s)
- Jia-Jia Zhang
- School of Pharmacy, Zhejiang Pharmaceutical College, Ningbo, Zhejiang 315100, P.R. China
| | - Ke-Qi Zhu
- Department of Traditional Chinese Internal Medicine, Ningbo No. 1 Hospital, Ningbo, Zhejiang 315010, P.R. China
| |
Collapse
|
19
|
Glycosylated Triterpenoids as Endosomal Escape Enhancers in Targeted Tumor Therapies. Biomedicines 2017; 5:biomedicines5020014. [PMID: 28536357 PMCID: PMC5489800 DOI: 10.3390/biomedicines5020014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 12/19/2022] Open
Abstract
Protein-based targeted toxins play an increasingly important role in targeted tumor therapies. In spite of their high intrinsic toxicity, their efficacy in animal models is low. A major reason for this is the limited entry of the toxin into the cytosol of the target cell, which is required to mediate the fatal effect. Target receptor bound and internalized toxins are mostly either recycled back to the cell surface or lysosomally degraded. This might explain why no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date although more than 500 targeted toxins have been developed within the last decades. To overcome the problem of insufficient endosomal escape, a number of strategies that make use of diverse chemicals, cell-penetrating or fusogenic peptides, and light-induced techniques were designed to weaken the membrane integrity of endosomes. This review focuses on glycosylated triterpenoids as endosomal escape enhancers and throws light on their structure, the mechanism of action, and on their efficacy in cell culture and animal models. Obstacles, challenges, opportunities, and future prospects are discussed.
Collapse
|
20
|
Huth K, Heek T, Achazi K, Kühne C, Urner LH, Pagel K, Dernedde J, Haag R. Noncharged and Charged Monodendronised Perylene Bisimides as Highly Fluorescent Labels and their Bioconjugates. Chemistry 2017; 23:4849-4862. [DOI: 10.1002/chem.201605847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/20/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Katharina Huth
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| | - Timm Heek
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| | - Katharina Achazi
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| | - Christian Kühne
- Institute of Laboratory Medicine; Clinical Chemistry and Pathobiochemistry; Charité; Universitätsmedizin Berlin; Augustenburger Platz 1 13353 Berlin Germany
| | - Leonhard H. Urner
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| | - Kevin Pagel
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| | - Jens Dernedde
- Institute of Laboratory Medicine; Clinical Chemistry and Pathobiochemistry; Charité; Universitätsmedizin Berlin; Augustenburger Platz 1 13353 Berlin Germany
| | - Rainer Haag
- Institute of Chemistry and Biochemistry; Organic Chemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
| |
Collapse
|
21
|
Smith WS, Baker EJ, Holmes SE, Koster G, Hunt AN, Johnston DA, Flavell SU, Flavell DJ. Membrane cholesterol is essential for triterpenoid saponin augmentation of a saporin-based immunotoxin directed against CD19 on human lymphoma cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:993-1007. [PMID: 28235471 DOI: 10.1016/j.bbamem.2017.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 01/06/2023]
Abstract
Triterpenoid saponins from Saponinum Album (SA) exert potent lytic effects on eukaryotic cell plasma membranes and, when used at sub-lytic concentrations, significantly augment the cytotoxicity of saporin-based immunotoxins (IT). To help elucidate the mechanism(s) behind these two phenomena we investigated the role of cholesterol to both. Human Daudi lymphoma cells were lipid deprived using a combination of three different approaches. Following treatment, the total cellular lipid content was analyzed by electrospray ionization mass spectrometry (ESI-MS) and plasma membrane (PM) cholesterol content measured using the lipophilic fluorescent probe NR12S. Maximal lipid deprivation of cells resulted in a complete loss of sensitivity to lysis by SA. Similarly augmentation of the anti-CD19 immunotoxin (IT) BU12-SAPORIN by SA was lost but without a concomitant loss of intrinsic IT cytotoxicity. The lytic activity of SA was restored following incubation of lipid deprived Daudi cells with Synthecol or LDL. The augmentative effect of SA on IT cytotoxicity for Daudi cells was restored following repletion of PM cholesterol levels with LDL. NR12S fluorescence and ESI-MS analysis of cellular lipids demonstrated that restoration of SA lytic activity by Synthecol was entirely due to increased PM cholesterol levels. Restoration of cellular and PM cholesterol levels by LDL also restored the augmentative effect of SA for IT, an effect associated with repletion of PM cholesterol with minor changes in some phospholipid species. These results indicate that the lytic and IT augmentative properties of SA are cholesterol-dependent in contrast to intrinsic IT cytotoxicity that is at least partially cholesterol independent.
Collapse
Affiliation(s)
- Wendy S Smith
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom
| | - Ella J Baker
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom; Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Suzanne E Holmes
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom
| | - Grielof Koster
- NIHR Respiratory Biomedical Research Unit, UHS, University of Southampton School of Medicine, Southampton General Hospital, Southampton SO16 6YD, United Kingdom; Clinical and Experimental Sciences, University of Southampton School of Medicine, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
| | - Alan N Hunt
- Clinical and Experimental Sciences, University of Southampton School of Medicine, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton School of Medicine, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
| | - Sopsamorn U Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom
| | - David J Flavell
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital, Southampton, Hampshire SO16 6YD, United Kingdom.
| |
Collapse
|
22
|
Augmenting the Efficacy of Immunotoxins and Other Targeted Protein Toxins by Endosomal Escape Enhancers. Toxins (Basel) 2016; 8:toxins8070200. [PMID: 27376327 PMCID: PMC4963833 DOI: 10.3390/toxins8070200] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
The toxic moiety of almost all protein-based targeted toxins must enter the cytosol of the target cell to mediate its fatal effect. Although more than 500 targeted toxins have been investigated in the past decades, no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date. Missing efficacy can be attributed in many cases to insufficient endosomal escape and therefore subsequent lysosomal degradation of the endocytosed toxins. To overcome this drawback, many strategies have been described to weaken the membrane integrity of endosomes. This comprises the use of lysosomotropic amines, carboxylic ionophores, calcium channel antagonists, various cell-penetrating peptides of viral, bacterial, plant, animal, human and synthetic origin, other organic molecules and light-induced techniques. Although the efficacy of the targeted toxins was typically augmented in cell culture hundred or thousand fold, in exceptional cases more than million fold, the combination of several substances harbors new problems including additional side effects, loss of target specificity, difficulties to determine the therapeutic window and cell type-dependent variations. This review critically scrutinizes the chances and challenges of endosomal escape enhancers and their potential role in future developments.
Collapse
|
23
|
Giansanti F, Sabatini D, Pennacchio MR, Scotti S, Angelucci F, Dhez AC, Antonosante A, Cimini A, Giordano A, Ippoliti R. PDZ Domain in the Engineering and Production of a Saporin Chimeric Toxin as a Tool for targeting Cancer Cells. J Cell Biochem 2016; 116:1256-66. [PMID: 25581839 DOI: 10.1002/jcb.25080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/06/2015] [Indexed: 11/07/2022]
Abstract
In this paper we have studied a PDZ protein domain as a possible tool for cellular targeting of the ribosome inactivating protein Saporin, exploiting the ability of PDZ domains to recognize and bind short peptide sequences located at the C-terminus of a cognate protein. We have focused our attention on the PDZ domain from hCASK (Human calcium/calmodulin-dependent serine protein kinase) that binds extracellular CD98 in epithelial cells, being this antigen recognized as a marker for several human tumors and particularly considered a negative prognostic marker for human glioblastoma. We produced recombinant fusions of one or two hCASK-PDZ domains with the ribosome inactivating protein Saporin and assayed them on two human glioblastoma cell lines (GL15 and U87). These constructs proved to be toxic, with increasing activity as a function of the number of PDZ domains, and induce cell death by apoptotic mechanisms in a dose-dependent and/or time dependent manner.
Collapse
Affiliation(s)
- Francesco Giansanti
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Domenica Sabatini
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Maria Rosaria Pennacchio
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Stefano Scotti
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Francesco Angelucci
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Anne-Chloè Dhez
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Andrea Antonosante
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| | - Annamaria Cimini
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy.,Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, Pennsylvania
| | - Antonio Giordano
- Department of Medical, Surgery & Neurosciences, University of Siena, Italy.,Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, Pennsylvania
| | - Rodolfo Ippoliti
- Department of Health, Life and Environmental Sciences, University of L'Aquila, I-67100 L'Aquila, Italy
| |
Collapse
|
24
|
Gilabert-Oriol R, Weng A, Trautner A, Weise C, Schmid D, Bhargava C, Niesler N, Wookey PJ, Fuchs H, Thakur M. Combinatorial approach to increase efficacy of Cetuximab, Panitumumab and Trastuzumab by dianthin conjugation and co-application of SO1861. Biochem Pharmacol 2015; 97:247-55. [PMID: 26253687 DOI: 10.1016/j.bcp.2015.07.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 07/31/2015] [Indexed: 12/20/2022]
Abstract
The therapeutic relevance of immunotoxins is based on the conjugation of monoclonal antibodies to toxins. In cancer therapies, the conjugated antibodies not only direct the binding of immunotoxins to cancer-specific receptors and mediate the elimination of tumor cells through the innate immune system, but also increase target cytotoxicity by the intrinsic toxin activity. In the present study, the therapeutic antibodies Cetuximab (anti-EGFR, Erbitux(®)), Panitumumab (anti-EGFR, Vectibix(®)) and Trastuzumab (anti-HER2, Herceptin(®)) were chemically conjugated to the toxin dianthin. In the first instance, recombinant dianthin was characterized by mass spectrometry and its stability was analyzed by circular dichroism. Dianthin showed increased cytotoxicity on MCF-7 cells when tested in combination with a glycosylated triterpenoid (SO1861) in a real-time impedance-based cytotoxicity assay. In data obtained by live cell imaging, SO1861 specifically mediated the endo/lysosomal escape of dianthin without disrupting the plasma membrane. The purity of immunotoxins was confirmed by SDS-PAGE and Western blot. Their cytotoxicity was evaluated in the presence of SO1861 and dianthin-Cetuximab presented a GI50 (50% growth inhibition) of 5.3pM, dianthin-Panitumumab of 1.5pM, and dianthin-Trastuzumab of 23pM. Finally, the specificity of these immunotoxins was validated in a fluorescence-based real-time assay, where their binding to target cells was prevented by preincubation with an excess of label-free unconjugated antibody. Based on these data, we propose the use of dianthin and SO1861 as a new platform technology to enhance the efficacy of therapeutic antibodies.
Collapse
Affiliation(s)
- Roger Gilabert-Oriol
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany; Department of Medicine, University of Melbourne, Austin Health, Studley Road, VIC 3084 Heidelberg, Australia
| | - Alexander Weng
- Institut für Pharmazie-Pharmazeutische Biologie, Freie Universität Berlin, Königin-Luise-Straße 2+4, D-14195 Berlin, Germany
| | - Alexandra Trautner
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Christoph Weise
- Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, D-14195 Berlin, Germany
| | - Daniel Schmid
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Cheenu Bhargava
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Nicole Niesler
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Peter J Wookey
- Department of Medicine, University of Melbourne, Austin Health, Studley Road, VIC 3084 Heidelberg, Australia
| | - Hendrik Fuchs
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Mayank Thakur
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany.
| |
Collapse
|
25
|
Improved intracellular delivery of peptide- and lipid-nanoplexes by natural glycosides. J Control Release 2015; 206:75-90. [PMID: 25758332 DOI: 10.1016/j.jconrel.2015.03.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/05/2015] [Accepted: 03/06/2015] [Indexed: 12/29/2022]
Abstract
Targeted nanocarriers undergo endocytosis upon binding to their membrane receptors and are transported into cellular compartments such as late endosomes and lysosomes. In gene delivery the genetic material has to escape from the cellular compartments into the cytosol. The process of endosomal escape is one of the most critical steps for successful gene delivery. For this reason synthetic lipids with fusogenic properties such as 2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) are integrated into the nanocarriers. In this study we show that a natural, plant derived glycoside (SO1861) from Saponaria officinalis L. greatly improves the efficacy of lipid based as well as non-lipid based targeted nanoplexes consisting of a targeted K16 peptide with a nucleic acid binding domain and plasmid-DNA, minicircle-DNA or small interfering RNA (siRNA). By confocal live cell imaging and single cell analyses, we demonstrate that SO1861 augments the escape of the genetic cargo out of the intracellular compartments into the cytosol. Co-localisation experiments with fluorescence labelled dextran and transferrin indicate that SO1861 induces the release of the genetic cargo out of endosomes and lysosomes. However, the transduction efficacy of a lentivirus based gene delivery system was not augmented. In order to design receptor-targeted nanoplexes (LPD) with improved functional properties, SO1861 was integrated into the lipid matrix of the LPD. The SO1861 sensitized LPD (LPDS) were characterized by dynamic light scattering and transmission electron microscopy. Compared to their LPD counterparts the LPDS-nanoplexes showed a greatly improved gene delivery. As shown by differential scanning calorimetry SO1861 can be easily integrated into the lipid bilayer of glycerophospholipid model membranes. This underlines the great potential of SO1861 as a new transfection multiplier for non-viral gene delivery systems.
Collapse
|
26
|
Mallinckrodt BV, Thakur M, Weng A, Gilabert-Oriol R, Dürkop H, Brenner W, Lukas M, Beindorff N, Melzig MF, Fuchs H. Dianthin-EGF is an effective tumor targeted toxin in combination with saponins in a xenograft model for colon carcinoma. Future Oncol 2014; 10:2161-75. [DOI: 10.2217/fon.14.164] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
ABSTRACT Aims: The intention of this work was to lift saponin supported tumor targeted therapies onto the next level by using targeted toxins in nude mice xenotransplant models. Materials & methods: Combined application of dianthin coupled to EGF and saponin SO-1861 was tested in a xenograft model of colon carcinoma. In vitro cytotoxicity was tested in real-time in NIH3T3 cells (no human EGF receptor expression), HER14 and human colon carcinoma HCT116 (both EGF receptor overexpressing) cells. A xenograft model was established using HCT116 cells and tumor-bearing animals were treated with SO-1861 (30 µg/treatment) and dianthin coupled to EGF (0.35 µg/treatment). Tumor progression was monitored, using 18F-2-fluor-2-desoxy-d-glucose, by small animal PET and by x-ray computed tomography. Results: In vitro results demonstrated a high-receptor specificity and the in vivo experiment showed a progressive reduction of the tumor volume and glycolytic activity in the treated group (>95% reduction; p < 0.05). Conclusion: This therapy has great advantage because of high specificity, low side effects and great effectiveness for future development in the treatment of colon cancer.
Collapse
Affiliation(s)
- Benedicta von Mallinckrodt
- Institute for Laboratory Medicine, Clinical Chemistry & Pathobiochemistry, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Mayank Thakur
- Institute for Laboratory Medicine, Clinical Chemistry & Pathobiochemistry, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Alexander Weng
- Institute for Laboratory Medicine, Clinical Chemistry & Pathobiochemistry, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Roger Gilabert-Oriol
- Institute for Laboratory Medicine, Clinical Chemistry & Pathobiochemistry, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Horst Dürkop
- Pathodiagnostik Berlin, Referenzzentrum für Lymphom-und Hämatopathologie, Komturstraße 58, Berlin, Germany
| | - Winfried Brenner
- Department of Nuclear Medicine Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin
| | - Mathias Lukas
- Department of Nuclear Medicine Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Ismaninger Straße 22, 81675 Munich, Germany
| | - Nicola Beindorff
- Department of Nuclear Medicine Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin
| | - Matthias F Melzig
- Institute of Pharmacy, Free University Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany
| | - Hendrik Fuchs
- Institute for Laboratory Medicine, Clinical Chemistry & Pathobiochemistry, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| |
Collapse
|
27
|
Holmes SE, Bachran C, Fuchs H, Weng A, Melzig MF, Flavell SU, Flavell DJ. Triterpenoid saponin augmention of saporin-based immunotoxin cytotoxicity for human leukaemia and lymphoma cells is partially immunospecific and target molecule dependent. Immunopharmacol Immunotoxicol 2014; 37:42-55. [PMID: 25347443 DOI: 10.3109/08923973.2014.971964] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT Saponinum album (SA) is a complex mixture of triterpenoid saponins previously shown to augment the cytotoxicity of the type I ribosome-inactivating protein saporin and an EGF-saporin target toxin that could potentially be used to improve the therapeutic window of targeted toxins. OBJECTIVE To investigate the augmentative property of SA on saporin and saporin-based immunotoxins (IT) directed against five different cell surface target molecules on human leukemia and lymphoma cells. MATERIALS AND METHODS After determining the optimum dose of SA for each cell line, the extent of SA-mediated augmentation was established for saporin and five saporin-based ITs using XTT and an annexin V apoptosis assay. Immunospecificity was investigated using three different blocking assays. Dose-scheduling was also investigated using the XTT assay. RESULTS Uncorrected SA-mediated augmentation ranged at best from 31.5 million-fold to, at worse, 174-fold. However, when the calculated fold-increases were adjusted for the non-immunospecific effects of SA on an off-target IT, the true augmentative effects of SA were found to be largely non-immunospecific. Antibody blocking studies demonstrated that the augmentative effect of SA was only partially immunospecific. Separate exposure of target cells to IT and SA at different times demonstrated that immunospecific augmentation of IT by SA could be achieved but only if cells were exposed to IT first and SA second. CONCLUSIONS SA significantly, although variably, augments the cytotoxicity of saporin and saporin-based immunotoxins. Concomitant exposure to both IT and SA can result in non-immunospecific cytotoxicity that can be overcome by temporally separating exposure to each.
Collapse
Affiliation(s)
- Suzanne E Holmes
- The Simon Flavell Leukaemia Research Laboratory, Southampton General Hospital , Southampton , UK
| | | | | | | | | | | | | |
Collapse
|
28
|
Gilabert-Oriol R, Thakur M, von Mallinckrodt B, Bhargava C, Wiesner B, Eichhorst J, Melzig MF, Fuchs H, Weng A. Reporter assay for endo/lysosomal escape of toxin-based therapeutics. Toxins (Basel) 2014; 6:1644-66. [PMID: 24859158 PMCID: PMC4052257 DOI: 10.3390/toxins6051644] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 11/16/2022] Open
Abstract
Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters—horseradish peroxidase (HRP), Alexa Fluor 488 (Alexa) and ricin A-chain (RTA)—were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates—saporin-HRP, Alexasaporin and saporin-KQ-RTA—were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release) or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape) was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of Alexasaporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10–1000 nM.
Collapse
Affiliation(s)
- Roger Gilabert-Oriol
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| | - Mayank Thakur
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| | - Benedicta von Mallinckrodt
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| | - Cheenu Bhargava
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| | - Burkhard Wiesner
- Leibnizinstitut für Molekulare Pharmakologie (FMP), Berlin D-13125, Germany.
| | - Jenny Eichhorst
- Leibnizinstitut für Molekulare Pharmakologie (FMP), Berlin D-13125, Germany.
| | - Matthias F Melzig
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2 + 4, Berlin D-14195, Germany.
| | - Hendrik Fuchs
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| | - Alexander Weng
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, Berlin D-13353, Germany.
| |
Collapse
|
29
|
Gilabert-Oriol R, Weng A, Mallinckrodt BV, Melzig MF, Fuchs H, Thakur M. Immunotoxins constructed with ribosome-inactivating proteins and their enhancers: a lethal cocktail with tumor specific efficacy. Curr Pharm Des 2014; 20:6584-643. [PMID: 25341935 PMCID: PMC4296666 DOI: 10.2174/1381612820666140826153913] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 08/05/2014] [Indexed: 11/30/2022]
Abstract
The term ribosome-inactivating protein (RIP) is used to denominate proteins mostly of plant origin, which have N-glycosidase enzymatic activity leading to a complete destruction of the ribosomal function. The discovery of the RIPs was almost a century ago, but their usage has seen transition only in the last four decades. With the advent of antibody therapy, the RIPs have been a subject of extensive research especially in targeted tumor therapies, which is the primary focus of this review. In the present work we enumerate 250 RIPs, which have been identified so far. An attempt has been made to identify all the RIPs that have been used for the construction of immunotoxins, which are conjugates or fusion proteins of an antibody or ligand with a toxin. The data from 1960 onwards is reviewed in this paper and an extensive list of more than 450 immunotoxins is reported. The clinical reach of tumor-targeted toxins has been identified and detailed in the work as well. While there is a lot of potential that RIPs embrace for targeted tumor therapies, the success in preclinical and clinical evaluations has been limited mainly because of their inability to escape the endo/lysosomal degradation. Various strategies that can increase the efficacy and lower the required dose for targeted toxins have been compiled in this article. It is plausible that with the advancements in platform technologies or improved endosomal escape the usage of tumor targeted RIPs would see the daylight of clinical success.
Collapse
Affiliation(s)
| | | | | | | | | | - Mayank Thakur
- Institut fur Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charite - Universitatsmedizin Berlin, Campus Virchow-Klinikum (Forum 4), Augustenburger Platz 1, D-13353 Berlin, Germany.
| |
Collapse
|
30
|
Gilabert-Oriol R, Thakur M, von Mallinckrodt B, Hug T, Wiesner B, Eichhorst J, Melzig MF, Fuchs H, Weng A. Modified Trastuzumab and Cetuximab Mediate Efficient Toxin Delivery While Retaining Antibody-Dependent Cell-Mediated Cytotoxicity in Target Cells. Mol Pharm 2013; 10:4347-57. [DOI: 10.1021/mp400444q] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roger Gilabert-Oriol
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| | - Mayank Thakur
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| | - Benedicta von Mallinckrodt
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| | - Thomas Hug
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| | - Burkhard Wiesner
- Leibnizinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Jenny Eichhorst
- Leibnizinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Matthias F. Melzig
- Institut
für Pharmazie, Freie Universität Berlin, Königin-Luise-Straße
2+4, D-14195 Berlin, Germany
| | - Hendrik Fuchs
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| | - Alexander Weng
- Institut
für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm
30, D-12200 Berlin, Germany
| |
Collapse
|
31
|
Structure–activity relationships of saponins enhancing the cytotoxicity of ribosome-inactivating proteins type I (RIP-I). Toxicon 2013; 73:144-50. [DOI: 10.1016/j.toxicon.2013.07.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/09/2013] [Accepted: 07/16/2013] [Indexed: 11/23/2022]
|
32
|
Thakur M, Weng A, Pieper A, Mergel K, von Mallinckrodt B, Gilabert-Oriol R, Görick C, Wiesner B, Eichhorst J, Melzig MF, Fuchs H. Macromolecular interactions of triterpenoids and targeted toxins: role of saponins charge. Int J Biol Macromol 2013; 61:285-94. [PMID: 23887142 DOI: 10.1016/j.ijbiomac.2013.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/10/2013] [Accepted: 07/12/2013] [Indexed: 11/26/2022]
Abstract
Macromolecular interaction of protein toxins with certain plant triterpenoids holds potential for application in tumor therapy. The ability of only certain saponins to enhance the endosomal escape of toxins specifically in tumor cells was evaluated and set into correlation with the electrophoretic mobility. Saponins from Saponaria officinalis Linn, were selected as a lead to understand this evolutionarily conserved principle in detail. Agarose gel electrophoresis was utilized to procure pure saponin fractions with different electrophoretic mobility, which were tested for their ability to enhance the toxicity by live cell monitoring. Five fractions (SOG1-SOG5) were isolated with a relative electrophoretic mobility of (-0.05, 0.41, 0.59, 0.75 and 1.00) and evaluated using thin layer chromatography, HPLC, and mass spectroscopic analysis. Cytotoxicity experiments revealed highest effectiveness with SOG3. Live cell imaging experiments with SOG3 revealed that this saponin with a specific REM of 0.59 could assist in the lyso/endosomal release of the toxic payload without affecting the integrity of plasma membrane and could lead to the induction of apoptosis. This charge dependent enhancement was also found to be highly specific to type I ribosome inactivating proteins compared to bacterial toxins. Charge interaction of plant toxins and saponins with tumor cells, plays a major role in toxin specific modulation of response. The finding opens up newer ways of finding protein saponin interaction conserved evolutionarily and to test their role in endosomal escape of therapeutic molecules.
Collapse
Affiliation(s)
- Mayank Thakur
- Institute for Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Gilabert-Oriol R, Thakur M, Weise C, Dernedde J, von Mallinckrodt B, Fuchs H, Weng A. Small structural differences of targeted anti-tumor toxins result in strong variation of protein expression. Protein Expr Purif 2013; 91:54-60. [PMID: 23867360 DOI: 10.1016/j.pep.2013.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
Targeted anti-tumor toxins consist of a toxic functional moiety that is chemically linked or recombinantly fused to a cell-directing ligand. Ribosome-inactivating proteins (RIPs), especially type I RIPs such as saporin or dianthin, are commonly used as toxin components. Although expression of type I RIP-based fusion proteins is well reported, the achievement of higher protein yields in heterologous expression systems through innovative strategies is of major interest. In the present study, the targeted toxins (his)saporin-EGF (SE) and (his)dianthin-EGF (DE) were expressed as fusion proteins under identical expression conditions. However, the total amount of DE was nearly two-times higher than SE. The identity of the heterologously expressed targeted toxins was confirmed by mass spectrometric studies. Their biological specific activity, monitored in real time, was almost equal. Sequence alignment shows 84% identity and a structural comparison revealed five major differences, two of which affect the secondary structure resulting in a loop (SE) to β-strand (DE) conversion and one introduces a gap in SE (after position 57). In conclusion, these structural variations resulted in different protein expression levels while codon usage and toxicity to bacteria were excluded as a cause. Minor structural differences identified in this study may be considered responsible for the protection of DE from bacterial proteases and therefore may serve as a lead to modify certain domains in type I RIP-based targeted toxins.
Collapse
Affiliation(s)
- Roger Gilabert-Oriol
- Institut Für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
34
|
Diving through Membranes: Molecular Cunning to Enforce the Endosomal Escape of Antibody-Targeted Anti-Tumor Toxins. Antibodies (Basel) 2013. [DOI: 10.3390/antib2020209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
|
35
|
Real-time analysis of membrane permeabilizing effects of oleanane saponins. Bioorg Med Chem 2013; 21:2387-2395. [DOI: 10.1016/j.bmc.2013.01.061] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 11/20/2022]
|
36
|
Thakur M, Mergel K, Weng A, von Mallinckrodt B, Gilabert-Oriol R, Dürkop H, Melzig MF, Fuchs H. Targeted tumor therapy by epidermal growth factor appended toxin and purified saponin: an evaluation of toxicity and therapeutic potential in syngeneic tumor bearing mice. Mol Oncol 2012; 7:475-83. [PMID: 23298730 DOI: 10.1016/j.molonc.2012.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 12/12/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022] Open
Abstract
Targeted toxin-based therapeutics are hindered by poor intracellular uptake, limited stability and non-specific immune stimulation. To address these problems, ligand-targeted toxins in combination with low dose saponin mixtures have been adapted and tested in vivo in the past, however, undefined saponin raw mixtures are not suitable for use in clinical development. In the present work we therefore used a targeted toxin (Sap3-EGF, i.e. saporin fused to epidermal growth factor) in combination with a structurally defined isolated saponin m/z 1861 (SO-1861). In vitro evaluation confirmed a 6900-fold enhancement in the cytotoxic efficacy of Sap3-EGF against TSA-EGFR target cells. The required dose of the targeted toxin was appreciably reduced and there was a highly synergistic effect observed. An ex vivo hemolysis assay showed no or very less hemolysis up to 10 μg/mL of SO-1861. In the acute toxicity studies SO-1861 was found to be non-toxic up to a dose of 100 μg/treatment. The enzymes aspartate aminotransferase, alanine aminotransferase, and glutamate dehydrogenase did not show any statistically significant liver damage, which was further confirmed by histological examination. Additionally, creatinine was also similar to the control group thus ruling out damage to kidney. In vivo studies in a syngeneic BALB/c tumor model characterized by EGFR overexpression were done by applying 30 μg SO-1861 and 0.1 μg Sap3-EGF per treatment. A more than 90% reduction (p < 0.05) in the average tumor volume was observed by this combined therapy.
Collapse
Affiliation(s)
- Mayank Thakur
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Weng A, Thakur M, von Mallinckrodt B, Beceren-Braun F, Gilabert-Oriol R, Wiesner B, Eichhorst J, Böttger S, Melzig MF, Fuchs H. Saponins modulate the intracellular trafficking of protein toxins. J Control Release 2012; 164:74-86. [PMID: 23063550 DOI: 10.1016/j.jconrel.2012.10.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 09/27/2012] [Accepted: 10/01/2012] [Indexed: 02/01/2023]
Abstract
Type I ribosome inactivating proteins such as saporin from the plant Saponaria officinalis L. are widely used as toxin moieties of targeted anti-tumor toxins. For exerting cytotoxicity the toxin moieties have to be released into the cytosol of tumor cells. However the cytosolic transfer of toxin molecules into the cytosol is mostly an inefficient process. In this report we demonstrate that certain saponins, which are also biosynthesized by Saponaria officinalis L., specifically mediate the release of saporin out of the intracellular compartments into the cytosol without affecting the integrity of the plasma membrane. The relevant cellular compartments were identified as late endosomes and lysosomes. Further studies revealed that endosomal acidification is a prerequisite for the saponin-mediated release of saporin. Binding analysis demonstrated an association of the saponins with saporin in a pH-dependent manner. The applicability of the saponin-mediated effect was demonstrated in vivo in a syngeneic tumor model using a saporin-based targeted anti-tumor toxin in combination with characterized saponins.
Collapse
Affiliation(s)
- Alexander Weng
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Real time monitoring of the cell viability during treatment with tumor-targeted toxins and saponins using impedance measurement. Biosens Bioelectron 2012; 35:503-506. [PMID: 22498641 DOI: 10.1016/j.bios.2012.03.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/12/2012] [Accepted: 03/13/2012] [Indexed: 11/24/2022]
Abstract
This work describes the application of an impedance-based measurement for the real time evaluation of targeted tumor therapies in cell culture (HeLa cells). We used a treatment procedure that is well established in cells and mice. Therein, tumor cells are treated with a combination of an epidermal growth factor-based targeted toxin named SE and particular plant glycosides called saponins. In the present study HeLa cells were seeded in different numbers onto interdigitated electrode structures integrated into the bottom of a 96 well plate. The cells were treated with SE in the presence and absence of the saponin SpnS-1 (isolated from Saponaria officinalis roots). The impedance was directly correlated with the viability of the cells. As expected from known end point measurements, a concentration dependent enhancement of toxicity was observed; however, with the impedance measurement we were for the first time able to trace the temporal changes of cell death during the combination treatment. This substantially added to the understanding of initial cellular mechanisms in the augmentation of the toxicity of targeted toxins by saponins and indicated the superiority of real time monitoring over end point assays. The method is less labor intensive and label-free with ease of monitoring the effects at each time point.
Collapse
|
39
|
Weng A, Thakur M, Beceren-Braun F, Bachran D, Bachran C, Riese SB, Jenett-Siems K, Gilabert-Oriol R, Melzig MF, Fuchs H. The toxin component of targeted anti-tumor toxins determines their efficacy increase by saponins. Mol Oncol 2012; 6:323-32. [PMID: 22309811 DOI: 10.1016/j.molonc.2012.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 01/11/2012] [Accepted: 01/12/2012] [Indexed: 11/16/2022] Open
Abstract
Tumor-targeting protein toxins are composed of a toxic enzyme coupled to a specific cell binding domain that targets cancer-associated antigens. The anti-tumor treatment by targeted toxins is accompanied by dose-limiting side effects. The future prospects of targeted toxins for therapeutic use in humans will be determined by reduce side effects. Certain plant secondary metabolites (saponins) were shown to increase the efficacy of a particular epidermal growth factor receptor (EGFR)-targeted toxin, paralleled by a tremendous decrease of side effects. This study was conducted in order to investigate the effects of substituting different toxin moieties fused to an EGF ligand binding domain on the augmentative ability of saponins for each against therapeutic potential of the saponin-mediated efficacy increase for different anti-tumor toxins targeting the EGFR. We designed several EGFR-targeted toxins varying in the toxic moiety. Each targeted toxin was used in combination with a purified saponin (SA1641), isolated from the ornamental plant Gypsophila paniculata L. SA1641 was characterized and the SA1641-mediated efficacy increase was investigated on EGFR-transfected NIH-3T3 cells. We observed a high dependency of the SA1641-mediated efficacy increase on the nature of toxin used for the construction of the targeted toxin, indicating high specificity. Structural alignments revealed a high homology between saporin and dianthin-30, the two toxic moieties that benefit most from the combination with SA1641. We further demonstrate that SA1641 did not influence the plasma membrane permeability, indicating an intracellular interaction of SA1641 and the toxin components of targeted toxins. Surface plasmon resonance measurements point to a transient binding of SA1641 to the toxin components of targeted toxins.
Collapse
Affiliation(s)
- Alexander Weng
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|