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Ding GB, Cao H, Zhu C, Chen F, Ye J, Li BC, Yang P, Stauber RH, Qiao M, Li Z. Biosynthesized tumor acidity and MMP dual-responsive plant toxin gelonin for robust cancer therapy. Biomater Sci 2024; 12:346-360. [PMID: 38099814 DOI: 10.1039/d3bm01779f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Among all kinds of anticancer agents, small molecule drugs produce an unsatisfactory therapeutic effect due to the lack of selectivity, notorious drug resistance and side effects. Therefore, researchers have begun to pay extensive attention to macromolecular drugs with high efficacy and specificity. As a plant toxin, gelonin exerts potent antitumor activity via inhibiting intracellular protein synthesis. However, gelonin lacks a translocation domain, and thus its poor cellular uptake leads to low outcomes of antitumor response. Here, tumor acidity and matrix metalloproteinase (MMP) dual-responsive functional gelonin (Trx-PVGLIG-pHLIP-gelonin, TPpG), composed of a thioredoxin (Trx) tag, a pH low insertion peptide (pHLIP), an MMP-responsive motif PVGLIG hexapeptide and gelonin, was innovatively proposed and biologically synthesized by a gene recombination technique. TPpG exhibited good thermal and serum stability, showed MMP responsiveness and could enter tumor cells under weakly acidic conditions, especially for MMP2-overexpressing HT1080 cells. Compared to low MMP2-expressing MCF-7 cells, TPpG displayed enhanced in vitro antitumor efficacy to HT1080 cells at pH 6.5 as determined by different methods. Likewise, TPpG was much more effective in triggering cell apoptosis and inhibiting protein synthesis in HT1080 cells than in MCF-7 cells. Intriguingly, with enhanced stability and pH/MMP dual responsiveness, TPpG notably inhibited subcutaneous HT1080 xenograft growth in mice and no noticeable off-target side effect was observed. This ingeniously designed strategy aims at providing new perspectives for the development of a smart platform that can intelligently respond to a tumor microenvironment for efficient protein delivery.
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Affiliation(s)
- Guo-Bin Ding
- Institutes of Biomedical Sciences/School of Life Sciences, Inner Mongolia University, Hohhot 010070, China.
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Huiyan Cao
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Chenchen Zhu
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Fangyuan Chen
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Jiaqi Ye
- Institutes of Biomedical Sciences/School of Life Sciences, Inner Mongolia University, Hohhot 010070, China.
| | - Bin-Chun Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Peng Yang
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Roland H Stauber
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
- Nanobiomedicine Department/ENT, University Medical Center Mainz, Mainz 55131, Germany
| | - Mingqiang Qiao
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
| | - Zhuoyu Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China.
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Schlaak L, Weise C, Kuropka B, Weng A. Sapovaccarin-S1 and -S2, Two Type I RIP Isoforms from the Seeds of Saponaria vaccaria L. Toxins (Basel) 2022; 14:toxins14070449. [PMID: 35878187 PMCID: PMC9324600 DOI: 10.3390/toxins14070449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 02/06/2023] Open
Abstract
Type I ribosome-inactivating proteins (RIPs) are plant toxins that inhibit protein synthesis by exerting rRNA N-glycosylase activity (EC 3.2.2.22). Due to the lack of a cell-binding domain, type I RIPs are not target cell-specific. However once linked to antibodies, so called immunotoxins, they are promising candidates for targeted anti-cancer therapy. In this study, sapovaccarin-S1 and -S2, two newly identified type I RIP isoforms differing in only one amino acid, were isolated from the seeds of Saponaria vaccaria L. Sapovaccarin-S1 and -S2 were purified using ammonium sulfate precipitation and subsequent cation exchange chromatography. The determined molecular masses of 28,763 Da and 28,793 Da are in the mass range typical for type I RIPs and the identified amino acid sequences are homologous to known type I RIPs such as dianthin 30 and saporin-S6 (79% sequence identity each). Sapovaccarin-S1 and -S2 showed adenine-releasing activity and induced cell death in Huh-7 cells. In comparison to other type I RIPs, sapovaccarin-S1 and -S2 exhibited a higher thermostability as shown by nano-differential scanning calorimetry. These results suggest that sapovaccarin-S1 and -S2 would be optimal candidates for targeted anti-cancer therapy.
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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;
- Correspondence: ; Tel.: +49-30-838-51265
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Wang F, Wu P, Qin S, Deng Y, Han P, Li X, Fan C, Xu Y. Curcin C inhibit osteosarcoma cell line U2OS proliferation by ROS induced apoptosis, autophagy and cell cycle arrest through activating JNK signal pathway. Int J Biol Macromol 2022; 195:433-439. [PMID: 34896468 DOI: 10.1016/j.ijbiomac.2021.11.156] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022]
Abstract
Osteosarcoma is a kind of primary bone malignant tumors. Its cure rate has been stagnant in the past decade years. Curcin C belongs to type I ribosome inactivating proteins, extracted from the cotyledons of post-germinated Jatropha curcas seeds. It can inhibit the proliferation of several tumor lines including U2OS cells with extraordinary efficiency. The treated U2OS cells were arrested in both S and G2/M phase, showed typical apoptosis morphological characteristic, formed autophagosomes and increase the ratio of LC3II to LC3I. Meanwhile, the level of ROS in the treated cells was found increasing significantly, with the change of mitochondrial membrane potential and decreased antioxidant enzyme activities. The application of ROS scavenger NAC not only significantly inhibited the toxicity of Curcin C but also prevented the happen of apoptosis and autophagy to some extent. These results suggested that Curcin C may function through ROS pathway. In addition, the Curcin C treatment could activate JNK and inhibit ERK signal pathway. Sp600125, an inhibitor of JNK signaling pathway, can prevent subsequent apoptosis and autophagy events, suggesting that JNK pathway was at least one of the pathways of Curcin C action. Moreover, the relevant including antagonistic among autophagy, apoptosis and cell cycle arresting induced by Curcin C also was found. In summary, it can be speculated that Curcin C may induce S, G2/M phase arrest, apoptosis and autophagy of human osteosarcoma U2OS cells through activating JNK signal pathway and blocking ERK signal pathway by promoting ROS accumulation in cell, thus finally reflected in the effect of inhibiting tumor cell proliferation.
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Affiliation(s)
- Fei Wang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Peng Wu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Siying Qin
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yushan Deng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Pan Han
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Xiao Li
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Caixin Fan
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Ying Xu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.
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Hassan Y, Ogg S, Ge H. Novel Binding Mechanisms of Fusion Broad Range Anti-Infective Protein Ricin A Chain Mutant-Pokeweed Antiviral Protein 1 (RTAM-PAP1) against SARS-CoV-2 Key Proteins in Silico. Toxins (Basel) 2020; 12:toxins12090602. [PMID: 32957454 PMCID: PMC7551812 DOI: 10.3390/toxins12090602] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 01/24/2023] Open
Abstract
The deadly pandemic named COVID-19, caused by a new coronavirus (SARS-CoV-2), emerged in 2019 and is still spreading globally at a dangerous pace. As of today, there are no proven vaccines, therapies, or even strategies to fight off this virus. Here, we describe the in silico docking results of a novel broad range anti-infective fusion protein RTAM-PAP1 against the various key proteins of SARS-CoV-2 using the latest protein-ligand docking software. RTAM-PAP1 was compared against the SARS-CoV-2 B38 antibody, ricin A chain, a pokeweed antiviral protein from leaves, and the lectin griffithsin using the special CoDockPP COVID-19 version. These experiments revealed novel binding mechanisms of RTAM-PAP1 with a high affinity to numerous SARS-CoV-2 key proteins. RTAM-PAP1 was further characterized in a preliminary toxicity study in mice and was found to be a potential therapeutic candidate. These findings might lead to the discovery of novel SARS-CoV-2 targets and therapeutic protein structures with outstanding functions.
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Affiliation(s)
- Yasser Hassan
- Ophiuchus Medicine Inc., Vancouver, BC V6B 0M3, Canada
- Correspondence:
| | - Sherry Ogg
- Biotechnology, Johns Hopkins University, AAP, Baltimore, MD 21218, USA;
| | - Hui Ge
- AscentGene Inc., Gaithersburg, MD 20878, USA;
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Scirè A, Tanfani F, Ausili A. A Spectroscopic Study on Secondary Structure and Thermal Unfolding of the Plant Toxin Gelonin Confirms Some Typical Structural Characteristics and Unravels the Sequence of Thermal Unfolding Events. Toxins (Basel) 2019; 11:toxins11090483. [PMID: 31443430 PMCID: PMC6783991 DOI: 10.3390/toxins11090483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 11/17/2022] Open
Abstract
Gelonin from the Indian plant Gelonium multiflorum belongs to the type I ribosome-inactivating proteins (RIPs). Like other members of RIPs, this toxin glycoprotein inhibits protein synthesis of eukaryotic cells; hence, it is largely used in the construction of immunotoxins composed of cell-targeted antibodies. Lysosomal degradation is one of the main issues in targeted tumor therapies, especially for type I RIP-based toxins, as they lack the translocation domains. The result is an attenuated cytosolic delivery and a decrease of the antitumor efficacy of these plant-derived toxins; therefore, strategies to permit their release from endosomal vesicles or modifications of the toxins to make them resistant to degradation are necessary to improve their efficacy. Using infrared spectroscopy, we thoroughly analyzed both the secondary structure and the thermal unfolding of gelonin. Moreover, by the combination of two-dimensional correlation spectroscopy and phase diagram method, it was possible to deduce the sequence of events during the unfolding, confirming the typical characteristic of the RIP members to denature in two steps, as a sequential loss of tertiary and secondary structure was detected at 58 °C and at 65 °C, respectively. Additionally, some discrepancies in the unfolding process between gelonin and saporin-S6, another type I RIP protein, were detected.
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Affiliation(s)
- Andrea Scirè
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Fabio Tanfani
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Alessio Ausili
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, 30100 Murcia, Spain.
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6
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Jiang Y, Pan X, Chang J, Niu W, Hou W, Kuai H, Zhao Z, Liu J, Wang M, Tan W. Supramolecularly Engineered Circular Bivalent Aptamer for Enhanced Functional Protein Delivery. J Am Chem Soc 2018; 140:6780-6784. [PMID: 29772170 PMCID: PMC6442730 DOI: 10.1021/jacs.8b03442] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Circular bivalent aptamers (cb-apt) comprise an emerging class of chemically engineered aptamers with substantially improved stability and molecular recognition ability. Its therapeutic application, however, is challenged by the lack of functional modules to control the interactions of cb-apt with therapeutics. We present the design of a β-cyclodextrin-modified cb-apt (cb-apt-βCD) and its supramolecular interaction with molecular therapeutics via host-guest chemistry for targeted intracellular delivery. The supramolecular ensemble exhibits high serum stability and enhanced intracellular delivery efficiency compared to a monomeric aptamer. The cb-apt-βCD ensemble delivers green fluorescent protein into targeted cells with efficiency as high as 80%, or cytotoxic saporin to efficiently inhibit tumor cell growth. The strategy of conjugating βCD to cb-apt, and subsequently modulating the supramolecular chemistry of cb-apt-βCD, provides a general platform to expand and diversify the function of aptamers, enabling new biological and therapeutic applications.
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Affiliation(s)
- Ying Jiang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, People’s Republic of China
- Center for Research at Bio/Nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Xiaoshu Pan
- Center for Research at Bio/Nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Jin Chang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Weijia Niu
- Center for Research at Bio/Nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Weijia Hou
- Center for Research at Bio/Nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Hailan Kuai
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, People’s Republic of China
| | - Zilong Zhao
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, People’s Republic of China
| | - Ji Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Ming Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, People’s Republic of China
- Institute of Molecular Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, and College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
- Center for Research at Bio/Nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
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7
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Zhang Y, Yang Q, Li C, Ding M, Lv X, Tao C, Yu H, Chen F, Xu Y. Curcin C, a novel type I ribosome-inactivating protein from the post-germinating cotyledons of Jatropha curcas. Amino Acids 2017; 49:1619-1631. [PMID: 28664270 DOI: 10.1007/s00726-017-2456-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/20/2017] [Indexed: 12/18/2022]
Abstract
A novel type I ribosome-inactivating protein (RIP), designated as curcin C, was purified from Jatropha curcas, an important feedback source of bio-fuel. Molecular mass and isoelectric point of curcin C were 31.398 kDa and 7.12 as detected by MALTI-TOF assay and capillary electrophoresis assay, respectively. N-terminal sequence and LC-MS/MS analyses confirmed that curcin C is a type I RIP having high homology, but not the exactly the same with curcin, another type 1 RIP isolated from the endosperm of J. curcas. It exhibited N-glycosidase activity and in vitro translation inhibition activity. Moreover, curcin C displayed a strong selectively anti-tumor activity on human cancer cells. Its cytotoxicity against osteosarcoma cell line U20S is even higher than that of Paclitaxel with IC50 of 0.019 μM. Purification and identification of curcin C not only suggested its potential in natural anticancer drug development, but also provide chance to understanding different cytotoxic action among different RIPs.
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Affiliation(s)
- Yangxue Zhang
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Qian Yang
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Chenyang Li
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Mengmeng Ding
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Xueyan Lv
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Chengqiu Tao
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Hongwu Yu
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Fang Chen
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Ying Xu
- Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China.
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Tarassoli SP, de Pinillos Bayona AM, Pye H, Mosse CA, Callan JF, MacRobert A, McHale AP, Nomikou N. Cathepsin B-degradable, NIR-responsive nanoparticulate platform for target-specific cancer therapy. Nanotechnology 2017; 28:055101. [PMID: 28029105 DOI: 10.1088/1361-6528/28/5/055101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Stimuli-responsive anticancer formulations can promote drug release and activation within the target tumour, facilitate cellular uptake, as well as improve the therapeutic efficacy of drugs and reduce off-target effects. In the present work, indocyanine green (ICG)-containing polyglutamate (PGA) nanoparticles were developed and characterized. Digestion of nanoparticles with cathepsin B, a matrix metalloproteinase overexpressed in the microenvironment of advanced tumours, decreased particle size and increased ICG cellular uptake. Incorporation of ICG in PGA nanoparticles provided the NIR-absorbing agent with time-dependent altered optical properties in the presence of cathepsin B. Having minimal dark toxicity, the formulation exhibited significant cytotoxicity upon NIR exposure. Combined use of the formulation with saporin, a ribosome-inactivating protein, resulted in synergistically enhanced cytotoxicity attributed to the photo-induced release of saporin from endo/lysosomes. The results suggest that this therapeutic approach can offer significant therapeutic benefit in the treatment of superficial malignancies, such as head and neck tumours.
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Affiliation(s)
- Sam P Tarassoli
- Division of Surgery & Interventional Science, University College London, Royal Free Hospital, Pond Street, NW3 2PF, London, UK
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9
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Gilabert-Oriol R, Thakur M, Haussmann K, Niesler N, Bhargava C, Görick C, Fuchs H, Weng A. Saponins from Saponaria officinalis L. Augment the Efficacy of a Rituximab-Immunotoxin. Planta Med 2016; 82:1525-1531. [PMID: 27392242 DOI: 10.1055/s-0042-110495] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Triterpenoidal saponins are synthesized in the roots of Saponaria officinalis L. The same plant is also a source for the toxin Saporin, which is a ribosome-inactivating protein. Triterpenoidal saponins are known to increase the cytotoxicity of Saporin by modulating its intracellular trafficking. Here, we investigated if the combinatorial effects elicited by purified saponins and Saporin can be applied to increase the therapeutic efficacy of the immunotoxin Saporin-Rituximab. First, saponins were purified by high-performance liquid chromatography. Thereafter, their intrinsic cytotoxicity was evaluated on Ramos cells with no observed effect up to 5 µg/mL, however, saponins increased the cytotoxicity of Saporin, while no influence was observed on its N-glycosidase activity. Saporin-Rituximab bound to CD20 in Ramos cells and, in the absence of saponins, had a GI50 (concentration inhibiting cell growth to 50 %) of 7 nM. However, in the presence of a nontoxic concentration of saponins, the GI50 of Saporin-Rituximab was 0.01 nM, a nearly 700-fold increase in efficacy. Moreover, two further immunotoxins, namely Saporin-anti-CD22 and Saporin-anti-CD25, were tested in combination with saponins yielding enhancement factors of 170-fold and 25-fold, respectively. All three receptors are present in Ramos cells and the differences in cytotoxicity enhancement may be explained by the differing expression levels of the cellular receptors. The application of purified saponins from S. officinalis L. is therefore a new strategy to potentially improve the cytotoxicity and therapeutic efficacy of Rituximab-immunotoxins for the treatment of B-cell lymphoma.
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Affiliation(s)
- Roger Gilabert-Oriol
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Mayank Thakur
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Katy Haussmann
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Nicole Niesler
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Cheenu Bhargava
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Cornelia Görick
- Institut für Pharmazie, Freie Universität Berlin, Berlin, Germany
| | - Hendrik Fuchs
- Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
| | - Alexander Weng
- Institut für Pharmazie, Freie Universität Berlin, Berlin, Germany
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Sgambati V, Pizzo E, Mezzacapo MC, Di Giuseppe AMA, Landi N, Poerio E, Di Maro A. Cytotoxic activity of chimeric protein PD-L4UWSCI(tr) does not appear be affected by specificity of inhibition mediated by anti-protease WSCI domain. Biochimie 2015; 107 Pt B:385-90. [PMID: 25457104 DOI: 10.1016/j.biochi.2014.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/12/2014] [Indexed: 02/07/2023]
Abstract
In a previously study, a type 1 ribosome inactivating protein (PD-L4) and a wheat subtilisin/chymotrypsin inhibitor (WSCI) were engineered into a chimeric protein (PD-L4UWSCI) that presented in addition to the same properties of both domains an intriguing selective cytotoxic action on murine tumor cells. This finding supported the idea that the protection of C-terminal region of PD-L4 could amplify its cytotoxic action by virtue of a greater resistance to proteases. Several authors indeed revealed that the cytotoxicity of RIPs depends not only on the intracellular routing, but also on the intrinsic resistance to proteolysis. In this regard in the present work we have produced a variant of chimeric protein, named PD-L4UWSCI(tr), changing the inhibitory specificity of WSCI domain. The purpose of this approach was to check if the cytotoxicity of the chimeric protein was altered depending on the properties of protease inhibitor domain or by a different fold of whole protein. Data collected supposedly indicate that WSCI domain contributes to cytotoxicity of chimeric protein exclusively from a structural point of view.
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11
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Rust A, Hassan HHA, Sedelnikova S, Niranjan D, Hautbergue G, Abbas SA, Partridge L, Rice D, Binz T, Davletov B. Two complementary approaches for intracellular delivery of exogenous enzymes. Sci Rep 2015; 5:12444. [PMID: 26207613 PMCID: PMC4513551 DOI: 10.1038/srep12444] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 06/26/2015] [Indexed: 01/08/2023] Open
Abstract
Intracellular delivery of biologically active proteins remains a formidable challenge in biomedical research. Here we show that biomedically relevant enzymes can be delivered into cells using a new DNA transfection reagent, lipofectamine 3000, allowing assessment of their intracellular functions. We also show that the J774.2 macrophage cell line exhibits unusual intracellular uptake of structurally and functionally distinct enzymes providing a convenient, reagent-free approach for evaluation of intracellular activities of enzymes.
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Affiliation(s)
| | | | | | | | | | | | | | - David Rice
- The University of Sheffield, Western Bank, Sheffield, UK
| | - Thomas Binz
- Medizinische Hochschule Hannover, Carl-Neuberg-Straße, Hannover, Germany
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12
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Di R, Tumer NE. Pokeweed antiviral protein: its cytotoxicity mechanism and applications in plant disease resistance. Toxins (Basel) 2015; 7:755-72. [PMID: 25756953 PMCID: PMC4379523 DOI: 10.3390/toxins7030755] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/11/2015] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Pokeweed antiviral protein (PAP) is a 29 kDa type I ribosome inactivating protein (RIP) found in pokeweed plants. Pokeweed produces different forms of PAP. This review focuses on the spring form of PAP isolated from Phytolacca americana leaves. PAP exerts its cytotoxicity by removing a specific adenine from the α-sarcin/ricin loop of the large ribosomal RNA. Besides depurination of the rRNA, PAP has additional activities that contribute to its cytotoxicity. The mechanism of PAP cytotoxicity is summarized based on evidence from the analysis of transgenic plants and the yeast model system. PAP was initially found to be anti-viral when it was co-inoculated with plant viruses onto plants. Transgenic plants expressing PAP and non-toxic PAP mutants have displayed broad-spectrum resistance to both viral and fungal infection. The mechanism of PAP-induced disease resistance in transgenic plants is summarized.
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Affiliation(s)
- Rong Di
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
| | - Nilgun E Tumer
- Department of Plant Biology and Pathology, Rutgers, the State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA.
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13
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Domashevskiy AV, Goss DJ. Pokeweed antiviral protein, a ribosome inactivating protein: activity, inhibition and prospects. Toxins (Basel) 2015; 7:274-98. [PMID: 25635465 PMCID: PMC4344624 DOI: 10.3390/toxins7020274] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/07/2015] [Accepted: 01/23/2015] [Indexed: 01/30/2023] Open
Abstract
Viruses employ an array of elaborate strategies to overcome plant defense mechanisms and must adapt to the requirements of the host translational systems. Pokeweed antiviral protein (PAP) from Phytolacca americana is a ribosome inactivating protein (RIP) and is an RNA N-glycosidase that removes specific purine residues from the sarcin/ricin (S/R) loop of large rRNA, arresting protein synthesis at the translocation step. PAP is thought to play an important role in the plant's defense mechanism against foreign pathogens. This review focuses on the structure, function, and the relationship of PAP to other RIPs, discusses molecular aspects of PAP antiviral activity, the novel inhibition of this plant toxin by a virus counteraction-a peptide linked to the viral genome (VPg), and possible applications of RIP-conjugated immunotoxins in cancer therapeutics.
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MESH Headings
- Animals
- Binding Sites
- Endoribonucleases/chemistry
- Fungal Proteins/chemistry
- Genome, Viral
- Humans
- Protein Isoforms
- RNA Caps/chemistry
- RNA Caps/genetics
- RNA Caps/metabolism
- RNA, Plant/chemistry
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Ribosome Inactivating Proteins, Type 1/chemistry
- Ribosome Inactivating Proteins, Type 1/genetics
- Ribosome Inactivating Proteins, Type 1/metabolism
- Ribosome Inactivating Proteins, Type 1/pharmacology
- Ribosomes/chemistry
- Ribosomes/metabolism
- Ricin/chemistry
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Affiliation(s)
- Artem V Domashevskiy
- John Jay College of Criminal Justice, Department of Sciences, City University of New York, 524 West 59th Street, New York, NY 10019, USA.
| | - Dixie J Goss
- Department of Chemistry, Hunter College, City University of New York and the Graduate Center, 695 Park Avenue, New York, NY 10065, USA.
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Li AJ, Wang Q, Dinh TT, Wiater MF, Eskelsen AK, Ritter S. Hindbrain catecholamine neurons control rapid switching of metabolic substrate use during glucoprivation in male rats. Endocrinology 2013; 154:4570-9. [PMID: 24064356 PMCID: PMC3836078 DOI: 10.1210/en.2013-1589] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Using the retrogradely transported immunotoxin, antidopamine β-hydroxylase-saporin (DSAP), we showed previously that hindbrain catecholamine neurons innervating corticotropin-releasing hormone neurons in the paraventricular nucleus of the hypothalamus are required for glucoprivation-induced corticosterone secretion. Here, we examine the metabolic consequences of the DSAP lesion in male rats using indirect calorimetry. Rats injected into the paraventricular nucleus of the hypothalamus with DSAP or saporin (SAP) control did not differ in energy expenditure or locomotor activity under any test condition. However, DSAP rats had a persistently higher respiratory exchange ratio (RER) than SAPs under basal conditions. Systemic 2-deoxy-D-glucose did not alter RER in DSAP rats but rapidly decreased RER in SAP controls, indicating that this DSAP lesion impairs the ability to switch rapidly from carbohydrate to fat metabolism in response to glucoprivic challenge. In SAP controls, 2-deoxy-D-glucose-induced decrease in RER was abolished by adrenalectomy but not adrenal denervation. Furthermore, dexamethasone, a synthetic glucocorticoid, decreased RER in both SAP and DSAP rats. Thus, rapid switching of metabolic substrate use during glucoprivation appears to be due to impairment of the catecholamine-mediated increase in corticosterone secretion. Sustained elevation of basal RER in DSAP rats indicates that catecholamine neurons also influence metabolic functions that conserve glucose under basal conditions.
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Affiliation(s)
- Ai-Jun Li
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7620.
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15
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Mittelman-Smith MA, Williams H, Krajewski-Hall SJ, Lai J, Ciofi P, McMullen NT, Rance NE. Arcuate kisspeptin/neurokinin B/dynorphin (KNDy) neurons mediate the estrogen suppression of gonadotropin secretion and body weight. Endocrinology 2012; 153:2800-12. [PMID: 22508514 PMCID: PMC3359616 DOI: 10.1210/en.2012-1045] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/21/2012] [Indexed: 01/08/2023]
Abstract
Estrogen withdrawal increases gonadotropin secretion and body weight, but the critical cell populations mediating these effects are not well understood. Recent studies have focused on a subpopulation of hypothalamic arcuate neurons that coexpress estrogen receptor α, neurokinin 3 receptor (NK(3)R), kisspeptin, neurokinin B, and dynorphin for the regulation of reproduction. To investigate the function of kisspeptin/neurokinin B/dynorphin (KNDy) neurons, a novel method was developed to ablate these cells using a selective NK(3)R agonist conjugated to the ribosome-inactivating toxin, saporin (NK(3)-SAP). Stereotaxic injections of NK(3)-SAP in the arcuate nucleus ablated KNDy neurons, as demonstrated by the near-complete loss of NK(3)R, NKB, and kisspeptin-immunoreactive (ir) neurons and depletion of the majority of arcuate dynorphin-ir neurons. Selectivity was demonstrated by the preservation of proopiomelanocortin, neuropeptide Y, and GnRH-ir elements in the arcuate nucleus and median eminence. In control rats, ovariectomy (OVX) markedly increased serum LH, FSH, and body weight, and these parameters were subsequently decreased by treatment with 17β-estradiol. KNDy neuron ablation prevented the rise in serum LH after OVX and attenuated the rise in serum FSH. KNDy neuron ablation did not completely block the suppressive effects of E(2) on gonadotropin secretion, a finding consistent with redundant pathways for estrogen negative feedback. However, regardless of estrogen status, KNDy-ablated rats had lower levels of serum gonadotropins compared with controls. Surprisingly, KNDy neuron ablation prevented the dramatic effects of OVX and 17β-estradiol (E(2)) replacement on body weight and abdominal girth. These data provide evidence that arcuate KNDy neurons are essential for tonic gonadotropin secretion, the rise in LH after removal of E(2), and the E(2) modulation of body weight.
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Affiliation(s)
- Melinda A Mittelman-Smith
- Department of Pathology and the Evelyn F. McKnight Brain Institute, University of Arizona College of Medicine, Tucson, Arizona 85724, USA
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16
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He W, King AJ, Khan MA, Cuevas JA, Ramiaramanana D, Graham IA. Analysis of seed phorbol-ester and curcin content together with genetic diversity in multiple provenances of Jatropha curcas L. from Madagascar and Mexico. Plant Physiol Biochem 2011; 49:1183-90. [PMID: 21835630 DOI: 10.1016/j.plaphy.2011.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/11/2011] [Indexed: 05/08/2023]
Abstract
Jatropha curcas L. has been promoted as an oilseed crop for use to meet the increased world demand for vegetable oil production, and in particular, as a feedstock for biodiesel production. Seed meal is a protein-rich by-product of vegetable oil extraction, which can either be used as an organic fertilizer, or converted to animal feed. However, conversion of J. curcas seed meal into animal feed is complicated by the presence of toxins, though plants producing "edible" or "non-toxic" seeds occur in Mexico. Toxins present in the seeds of J. curcas include phorbol esters and a type-I ribosome inactivating protein (curcin). Although the edible seeds of J. curcas are known to lack phorbol esters, the curcin content of these seeds has not previously been studied. We analyzed the phorbol ester and curcin content of J. curcas seeds obtained from Mexico and Madagascar, and conclude that while phorbol esters are lacking in edible seeds, both types contain curcin. We also analyzed spatial distribution of these toxins in seeds. Phorbol-esters were most concentrated in the tegmen. Curcin was found in both the endosperm and tegmen. We conclude that seed toxicity in J. curcas is likely to be due to a monogenic trait, which may be under maternal control. We also conducted AFLP analysis and conclude that genetic diversity is very limited in the Madagascan collection compared to the Mexican collection.
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Affiliation(s)
- Wei He
- Centre for Novel Agricultural Products, Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
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17
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Polito L, Bortolotti M, Pedrazzi M, Bolognesi A. Immunotoxins and other conjugates containing saporin-s6 for cancer therapy. Toxins (Basel) 2011; 3:697-720. [PMID: 22069735 PMCID: PMC3202841 DOI: 10.3390/toxins3060697] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 05/27/2011] [Accepted: 06/03/2011] [Indexed: 11/18/2022] Open
Abstract
Ribosome-inactivating proteins (RIPs) are a family of plant toxins that permanently damage ribosomes and possibly other cellular substrates, thus causing cell death. RIPs are mostly divided in two types: Type 1 RIPs that are single-chain enzymatic proteins, and type 2 RIPs that consist of an active A chain (similar to a type 1 RIP) linked to a B chain with lectin properties. RIP-containing conjugates have been used in many experimental strategies against cancer cells, often showing great efficacy in clinical trials. Saporin-S6, a type 1 RIP extracted from Saponaria officinalis L. seeds, has been extensively utilized to construct anti-cancer conjugates because of its high enzymatic activity, stability and resistance to conjugation procedures, resulting in the efficient killing of target cells. This review summarizes saporin-S6-containing conjugates and their application in cancer therapy, considering in-vitro and in-vivo studies both in animal models and in clinical trials. The review is structured on the basis of the targeting of hematological versus solid tumors and on the antigen recognized on the cell surface.
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Affiliation(s)
- Letizia Polito
- Department of Experimental Pathology, "Alma Mater Studiorum" University of Bologna, via San Giacomo 14, 40126-Bologna, Italy.
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18
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Lyons AM, Thiele TE. Neuropeptide Y conjugated to saporin alters anxiety-like behavior when injected into the central nucleus of the amygdala or basomedial hypothalamus in BALB/cJ mice. Peptides 2010; 31:2193-9. [PMID: 20863864 PMCID: PMC2971693 DOI: 10.1016/j.peptides.2010.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 09/08/2010] [Accepted: 09/10/2010] [Indexed: 10/19/2022]
Abstract
Neuropeptide Y (NPY) is a 36-amino-acid neuromodulator that is distributed throughout the central nervous system and has been implicated in a wide range of neurobiological responses including the integration of emotional behavior. The anxiolytic properties of NPY are modulated by NPY signaling in the hippocampus and in the central (CeA) and basolateral (BLA) nuclei of the amygdala. Recently, the neurotoxin saporin, when conjugated to NPY (NPY-SAP), was shown to selectively kill NPY receptor-expressing neurons and has been used as a tool to study the central NPY neurocircuitry involved with feeding behaviors. Here we determined if NPY-SAP can be used as a tool to study the central NPY neurocircuitry that modulates anxiety-like behaviors. BALB/cJ mice were given injection of either NPY-SAP or a control blank saporin (B-SAP) into the CeA or the basomedial hypothalamus (BMH) as a control injection site. The elevated zero maze test was used to assess anxiety-like behavior and NPY-SAP-induced lesions were verified using NPY Y1 receptor (Y1R) immunoreactivity (IR). Results showed that injection of NPY-SAP into the CeA site-specifically blunted Y1R IR in the CeA which was associated with a significant increase in anxiety-like behavior. Injection of NPY-SAP into the BMH, while locally blunting Y1R IR, promoted a compensatory increase of Y1R IR in the BLA and the CA3 region of the hippocampus which was associated with a significant reduction of anxiety-like behavior. The present set of experiments suggest that the NPY-SAP neurotoxin may be a useful tool for studying the NPY neurocircuitry that modulates anxiety-like behaviors.
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Affiliation(s)
- Angela M. Lyons
- Psychology, University of North Carolina at Chapel Hill, CB#3270, Chapel Hill, NC, 27599-3270, USA
| | - Todd E. Thiele
- Psychology, University of North Carolina at Chapel Hill, CB#3270, Chapel Hill, NC, 27599-3270, USA
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, CB#7178, Chapel Hill, NC, 27599-7178, USA
- Address for Correspondence: Dr. Todd E. Thiele, Department of Psychology, University of North Carolina, Davie Hall CB# 3270, Chapel Hill, NC 27599-3270, Phone: (919) 962-1519, Fax: (919) 962-2537,
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19
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Baskin DG, Kim F, Gelling RW, Russell BJ, Schwartz MW, Morton GJ, Simhan HN, Moralejo DH, Blevins JE. A new oxytocin-saporin cytotoxin for lesioning oxytocin-receptive neurons in the rat hindbrain. Endocrinology 2010; 151:4207-13. [PMID: 20610562 PMCID: PMC2940497 DOI: 10.1210/en.2010-0295] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Evidence suggests that release of oxytocin in the nucleus tractus solitarius (NTS) of the hindbrain from descending projections that originate in the paraventricular nucleus can inhibit food intake by amplifying the satiety response to cholecystokinin (CCK). To further evaluate this mechanism in rats, we used a novel cytotoxin, saporin conjugated to oxytocin (OXY-SAP), a compound designed to destroy cells that express oxytocin receptors (OXYr). OXY-SAP was injected directly into the NTS to lesion neurons that express OXYr and that are implicated in potentiating CCK's satiety effects. The control consisted of injection of saporin conjugated to a nonsense peptide. We found that OXY-SAP was cytotoxic to human uterine smooth muscle cells in vitro, demonstrating that OXY-SAP can lesion cells that express OXYr. Using laser capture microdissection and real-time quantitative PCR, we demonstrated that OXYr mRNA levels were reduced in the NTS after OXY-SAP administration. Moreover, we found that OXY-SAP attenuated the efficacy of CCK-8 to reduce food intake and blocked the actions of an OXYr antagonist to stimulate food intake. The findings suggest that OXY-SAP is an effective neurotoxin for in vivo elimination of cells that express OXYr and is potentially useful for studies to analyze central nervous system mechanisms that involve the action of oxytocin on food intake and other physiological processes.
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Affiliation(s)
- Denis G Baskin
- Office of Research and Development Medical Research Service, Veterans Affairs Puget Sound Health Care System, Department of Veterans Affairs Medical Center, Seattle, Washington 98108, USA
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20
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Abstract
The gastrointestinal peptide, ghrelin, elicits feeding and secretion when administered systemically or centrally. Previous studies have suggested that hypothalamic projections of hindbrain catecholamine neurons are involved in both of these actions of ghrelin. The purpose of this study was to further assess the role of hindbrain catecholamine neurons in ghrelin-induced feeding and GH secretion and to determine the anatomical distribution of the catecholamine neurons involved. We lesioned noradrenergic and adrenergic neurons that innervate the medial hypothalamus by microinjecting the retrogradely transported immunotoxin, saporin (SAP) conjugated to antidopamine-beta-hydroxylase (DSAP) into the paraventricular nucleus of the hypothalamus. Controls were injected with unconjugated SAP. We found that the DSAP lesion did not impair the feeding response to central or peripheral ghrelin administration, indicating that these neurons are not required for ghrelin's orexigenic effect. However, the GH response to ghrelin was prolonged significantly in DSAP-lesioned rats. We also found that expression of Fos, an indicator of neuronal activation, was significantly enhanced over baseline levels in A1, A1/C1, C1, and A5 cell groups after ghrelin treatment and in A1, A1/C1, and A5 cell groups after GH treatment. The similar pattern of Fos expression in catecholamine cell groups after GH and ghrelin and the prolonged GH secretion in response to ghrelin in DSAP rats together suggest that activation of hindbrain catecholamine neurons by ghrelin or GH could be a component of a negative feedback response controlling GH levels.
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Affiliation(s)
- Alan J Emanuel
- Programs in Neuroscience, Washington State University, Pullman, WA 99164-6520, USA
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21
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Cao Y, Marks JD, Marks JW, Cheung LH, Kim S, Rosenblum MG. Construction and characterization of novel, recombinant immunotoxins targeting the Her2/neu oncogene product: in vitro and in vivo studies. Cancer Res 2009; 69:8987-95. [PMID: 19934334 DOI: 10.1158/0008-5472.can-09-2693] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The goal of this study was to characterize a series of anti-Her2/neu immunotoxin constructs to identify how different antibodies and linker choices affect the specificity and cytotoxicity of these proteins. We constructed a series of immunotoxins containing either the human single-chain antibody (scFv) C6.5 or the murine scFv e23 fused to the highly toxic recombinant gelonin (rGel) molecule. Based on the flexible GGGGS linker (L), the fusion construct C6.5-L-rGel was compared with e23-L-rGel to evaluate the specific cytotoxic effects against Her2/neu-positive and Her2/neu-negative tumor cells. Both constructs retained the specificity of the original antibody as well as the biological activity of rGel toxin. The two constructs displayed similar cytotoxicity against different carcinoma cells. We additionally introduced the modified linkers TRHRQPRGWEQL (Fpe) and AGNRVRRSVG (Fdt), which contained furin cleavage sites, to determine the effect of these design changes on stability and cell killing efficiency. The introduction of furin cleavage linkers (Fpe or Fdt) into the molecules resulted in dissimilar sensitivity to protease cleavage compared with the constructs containing the L linker, but very similar intracellular rGel release, cytotoxic kinetics, and induction of autophagic cell death in vitro. Xenograft studies with SKOV3 ovarian tumors were done using various C6.5/rGel constructs. C6.5-L-rGel was more efficient in tumor inhibition than constructs containing furin linkers, attributing to a higher stability in vivo of the L version. Therefore, our studies suggest that human C6.5-L-rGel may be an effective novel clinical agent for therapy of patients with Her2/neu-overexpressing malignancies.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/pharmacology
- Autophagy/drug effects
- Cell Line, Tumor
- Female
- Furin/pharmacology
- Humans
- Immunoglobulin Fragments/biosynthesis
- Immunoglobulin Fragments/chemistry
- Immunoglobulin Fragments/genetics
- Immunoglobulin Fragments/immunology
- Immunotoxins/chemistry
- Immunotoxins/genetics
- Immunotoxins/immunology
- Immunotoxins/pharmacology
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Oligopeptides/chemistry
- Ovarian Neoplasms/drug therapy
- Ovarian Neoplasms/enzymology
- Receptor, ErbB-2/biosynthesis
- Receptor, ErbB-2/immunology
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/pharmacology
- Recombinant Proteins/pharmacology
- Ribosome Inactivating Proteins, Type 1/chemistry
- Ribosome Inactivating Proteins, Type 1/genetics
- Ribosome Inactivating Proteins, Type 1/pharmacology
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Yu Cao
- Immunopharmacology and Targeted Therapy Laboratory, Department of Experimental Therapeutics, M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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22
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Nag N, Baxter MG, Berger-Sweeney JE. Efficacy of a murine-p75-saporin immunotoxin for selective lesions of basal forebrain cholinergic neurons in mice. Neurosci Lett 2009; 452:247-51. [PMID: 19150485 DOI: 10.1016/j.neulet.2009.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 01/02/2009] [Indexed: 11/18/2022]
Abstract
Selective lesioning of cholinergic neurons in the basal forebrain provides a tool for examining the functional significance of cholinergic loss, which is associated with a number of developmental and neurodegenerative disorders. A new version of an immunotoxin (murine-p75NTR-saporin) was used to produce a selective loss of cholinergic neurons in the adult basal forebrain of the mouse. This new version of the toxin is significantly more potent and selective than a previously developed version. C57Bl/6J mice (n=30) were given 1 microL of either saline or murine-p75NTR-saporin (0.65 microg/microL or 1.3 microg/microL) into the lateral ventricles, and then sacrificed 10-12 days post-surgery for histological analysis. In contrast to results from the previous version of the toxin, survival of the toxin-treated mice was 100% at both doses. A complete loss of cholinergic neurons was seen in the medial septum (MS) with both doses, while a dose-dependent loss of cholinergic neurons was observed in the nucleus basalis magnocellularis (nBM). The lesions were associated with locomotor hypoactivity and anxiolytic-type behavioral effects. These studies describe the efficacy and selectivity of this new version of murine-p75NTR-saporin, which may be used to provide insight into functional deficits that result from the loss of cholinergic neurons in the mouse basal forebrain.
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Affiliation(s)
- Nupur Nag
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA
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23
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Parente A, Conforto B, Di Maro A, Chambery A, De Luca P, Bolognesi A, Iriti M, Faoro F. Type 1 ribosome-inactivating proteins from Phytolacca dioica L. leaves: differential seasonal and age expression, and cellular localization. Planta 2008; 228:963-975. [PMID: 18704492 DOI: 10.1007/s00425-008-0796-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 07/18/2008] [Indexed: 05/26/2023]
Abstract
The expression of type 1 ribosome-inactivating proteins (RIPs) in Phytolacca dioica L. leaves was investigated. Fully expanded leaves of young P. dioica plants (up to 3 years old) expressed two novel RIPs, dioicin 1 and dioicin 2. The former was also found in developing leaves from adult P. dioica within about two and a half weeks after leaf development, and the latter continuously synthesized, with no seasonal or ontogenetic constraint. Fully expanded leaves from adult P. dioica expressed four RIPs (PD-Ls1-4) exhibiting seasonal variation. RIPs were localized in the extracellular space, in the vacuole and in the Golgi apparatus of mesophyll cells. Dioicin 1 and dioicin 2 showed rRNA N-beta-glycosidase activity and displayed the following properties, respectively: (1) Mr values of 30,047.00 and 29,910.00, (2) pIs of 8.74 and 9.37, and (3) IC(50) values of 19.74 (0.658 nM) and 6.85 ng/mL (0.229 nM). Furthermore, they showed adenine polynucleotide glycosylase activity and nicked pBR322 dsDNA. The amino acid sequence of dioicin 2 had 266 amino acid residues, and the highest percentage identity (81.6%) and similarity (84.6%) with PAP-II from Phytolacca americana, while its identity with other RIPs from Phytolaccaceae was around 40%.
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Affiliation(s)
- Augusto Parente
- Dipartimento di Scienze della Vita, Seconda Università di Napoli, Caserta, Italy.
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Göz D, Studholme K, Lappi DA, Rollag MD, Provencio I, Morin LP. Targeted destruction of photosensitive retinal ganglion cells with a saporin conjugate alters the effects of light on mouse circadian rhythms. PLoS One 2008; 3:e3153. [PMID: 18773079 PMCID: PMC2519834 DOI: 10.1371/journal.pone.0003153] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 08/11/2008] [Indexed: 11/18/2022] Open
Abstract
Non-image related responses to light, such as the synchronization of circadian rhythms to the day/night cycle, are mediated by classical rod/cone photoreceptors and by a small subset of retinal ganglion cells that are intrinsically photosensitive, expressing the photopigment, melanopsin. This raises the possibility that the melanopsin cells may be serving as a conduit for photic information detected by the rods and/or cones. To test this idea, we developed a specific immunotoxin consisting of an anti-melanopsin antibody conjugated to the ribosome-inactivating protein, saporin. Intravitreal injection of this immunotoxin results in targeted destruction of melanopsin cells. We find that the specific loss of these cells in the adult mouse retina alters the effects of light on circadian rhythms. In particular, the photosensitivity of the circadian system is significantly attenuated. A subset of animals becomes non-responsive to the light/dark cycle, a characteristic previously observed in mice lacking rods, cones, and functional melanopsin cells. Mice lacking melanopsin cells are also unable to show light induced negative masking, a phenomenon known to be mediated by such cells, but both visual cliff and light/dark preference responses are normal. These data suggest that cells containing melanopsin do indeed function as a conduit for rod and/or cone information for certain non-image forming visual responses. Furthermore, we have developed a technique to specifically ablate melanopsin cells in the fully developed adult retina. This approach can be applied to any species subject to the existence of appropriate anti-melanopsin antibodies.
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Affiliation(s)
- Didem Göz
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Keith Studholme
- Department of Psychiatry, Stony Brook University, Stony Brook, New York, United States of America
| | - Douglas A. Lappi
- Advanced Targeting Systems, San Diego, California, United States of America
| | - Mark D. Rollag
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Ignacio Provencio
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Lawrence P. Morin
- Department of Psychiatry, Stony Brook University, Stony Brook, New York, United States of America
- Program in Neuroscience, Medical Center, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
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25
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Weng A, Bachran C, Fuchs H, Melzig MF. Soapwort saponins trigger clathrin-mediated endocytosis of saporin, a type I ribosome-inactivating protein. Chem Biol Interact 2008; 176:204-11. [PMID: 18775419 DOI: 10.1016/j.cbi.2008.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 08/07/2008] [Accepted: 08/07/2008] [Indexed: 11/19/2022]
Abstract
Saporin, a type I ribosome-inactivating protein (RIP), removes adenine residues from the 28S ribosomal RNA as part of a process that leads to inhibition of protein synthesis. However, as shown in this study, neither saporin nor his-tagged saporin (both 0.6-6 pM) exert toxicity on several human cell lines including H-2171, SK-N-SH, HEP-G2, MOLT-3, THP-1, HL-60 and ECV-304. Saporin and his-tagged saporin became highly cytotoxic when they were used in a combined treatment with Soapwort saponins (SA). When combined with SA (2-4 microg/ml) saporin became as cytotoxic as the highly toxic type II RIP rViscumin reflected by an IC50 of 42.5x10(-12) M for saporin and 21.5x10(-12) M for rViscumin. We demonstrated that saporin was internalized via clathrin-mediated endocytosis, followed by the release into the endosomal transport system. Our results indicate that SA triggers this endocytic event rendering the otherwise cell membrane impermeable type I RIP saporin a potent cytotoxin. This effect was not cell line-specific suggesting that saporin exploits a common SA-dependent mechanism to enter cells.
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Affiliation(s)
- A Weng
- Institute of Pharmacy, Free University Berlin, D-14195 Berlin, Germany
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Sawasaki T, Nishihara M, Endo Y. RIP and RALyase cleave the sarcin/ricin domain, a critical domain for ribosome function, during senescence of wheat coleoptiles. Biochem Biophys Res Commun 2008; 370:561-5. [PMID: 18395011 DOI: 10.1016/j.bbrc.2008.03.124] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 03/22/2008] [Indexed: 11/30/2022]
Abstract
Type-I ribosome-inactivating protein (RIP), which is found in many plants, catalyzes depurination of a specific adenine in the sarcin/ricin domain (SRD) of the large rRNA causing loss of ribosomal activity. Previously, we found a RNA apurinic site-specific lyase (RALyase) that catalytically cleaved the phosphodiester bond at the RIP-dependent depurination site by beta-elimination reaction. Here we show that both the RIP activity and RIP-RALyase-mediated cleavage of SRD in the cytoplasmic ribosome were induced at the late stage of senescence of wheat coleoptiles. Following this process, tissue death was observed. Furthermore, transgenic tobacco plants expressing glucocorticoid-induced RIP developed senescence-like phenotype. Our results suggest that ribosome inactivation due to the cleavage of SRD by the inducible RIP and constitutively expressed RALyase may be a unique plant system that mediates programmed cell death at the late senescent stage.
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Affiliation(s)
- Tatsuya Sawasaki
- Cell-free Science and Technology Research Center, The Venture Business Laboratory, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
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Nagasawa Y, Fujii K, Yoshikawa T, Kobayashi Y, Kondo T. Pokeweed antiviral protein region Gly209-Lys225 is critical for RNA N-glycosidase activity of the prokaryotic ribosome. Phytochemistry 2008; 69:1653-1660. [PMID: 18377939 DOI: 10.1016/j.phytochem.2008.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 02/12/2008] [Accepted: 02/18/2008] [Indexed: 05/26/2023]
Abstract
Pokeweed antiviral protein (PAP) isolated from Phytolacca americana is a ribosome-inactivating protein (RIP) that has RNA N-glycosidase (RNG) activity towards both eukaryotic and prokaryotic ribosomes. In contrast, karasurin-A (KRN), a RIP from Trichosanthes kirilowii var. japonica, is active only on eukaryotic ribosomes. Stepwise selection of chimera proteins between PAP and KRN indicated that the C-terminal region of PAP (residues 209-225) was critical for RNG activity toward prokaryotic ribosomes. When the region of PAP (residues 209-225) was replaced with the corresponding region of KRN the PAP chimera protein, like KRN, was active only on eukaryotic ribosomes. Furthermore, insertion of the region of PAP (residues 209-225) into the KRN chimera protein resulted not only in the detectable RNG activity toward prokaryotic ribosome, but also activity toward the eukaryotic ribosomes as well that was seven-fold higher than for the original KRN. In this study, the possibility of genetic manipulation of the activity and substrate specificity of RIPs is demonstrated.
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Affiliation(s)
- Yoshimi Nagasawa
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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28
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Geden SE, Gardner RA, Fabbrini MS, Ohashi M, Phanstiel Iv O, Teter K. Lipopolyamine treatment increases the efficacy of intoxication with saporin and an anticancer saporin conjugate. FEBS J 2007; 274:4825-36. [PMID: 17714513 DOI: 10.1111/j.1742-4658.2007.06008.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Saporin is a type I ribosome-inactivating protein that is often appended with a cell-binding domain to specifically target and kill cancer cells. Urokinase plasminogen activator (uPA)-saporin, for example, is an anticancer toxin that consists of a chemical conjugate between the human uPA and native saporin. Both saporin and uPA-saporin enter the target cell by endocytosis and must then escape the endomembrane system to reach the cytosolic ribosomes. The latter process may represent a rate-limiting step for intoxication and would therefore directly affect toxin potency. In the present study, we document two treatments (shock with dimethylsulfoxide and lipopolyamine coadministration) that generate substantial cellular sensitization to saporin/uPA-saporin. With the use of lysosome-endosome X (LEX)1 and LEX2 mutant cell lines, an endosomal trafficking step preceding cargo delivery to the late endosomes was identified as a major site for the dimethylsulfoxide-facilitated entry of saporin into the cytosol. Dimethylsulfoxide and lipopolyamines are known to disrupt the integrity of endosome membranes, so these reagents could facilitate the rapid movement of toxin from permeabilized endosomes to the cytosol. However, the same pattern of toxin sensitization was not observed for dimethylsulfoxide- or lipopolyamine-treated cells exposed to diphtheria toxin, ricin, or the catalytic A chain of ricin. The sensitization effects were thus specific for saporin, suggesting a novel mechanism of saporin translocation by endosome disruption. Lipopolyamines have been developed as in vivo gene therapy vectors; thus, lipopolyamine coadministration with uPA-saporin or other saporin conjugates could represent a new approach for anticancer toxin treatments.
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Affiliation(s)
- Sandra E Geden
- Department of Molecular Biology and Microbiology and Biomolecular Science Center, University of Central Florida, FL, USA
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Ruggiero A, Chambery A, Di Maro A, Pisante M, Parente A, Berisio R. Crystallization and preliminary X-ray diffraction analysis of PD-L4, a ribosome inactivating protein from Phytolacca dioica L. leaves. Protein Pept Lett 2007; 14:97-100. [PMID: 17266657 DOI: 10.2174/092986607779117209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PD-L4, a type 1 ribosome inactivating protein from Phytolacca dioica leaves, has been successfully crystallized using vapour diffusion methods and PEG 4000 as a precipitant agent. In addition, crystals of a PD-L4 mutant, which has been recently observed to have a lower polynucleotide-adenosine glycosidase activity on DNA, rRNA and poly (A) substrates, have been obtained. To gather information on PD-L4 reaction mechanism both forms have been co-crystallized with adenine, the major product of their catalytic reaction. Diffraction patterns extend to atomic resolution and crystals belong to the orthorhombic P2(1)2(1)2(1) space group, with one molecule in the asymmetric unit. Structure determination has been achieved using molecular replacement; preliminary electron density maps have clearly given evidence of adenine binding.
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Affiliation(s)
- Alessia Ruggiero
- Istituto di Biostrutture e Bioimmagini, C.N.R., I-80134 Napoli, Italy
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Chambery A, de Donato A, Bolognesi A, Polito L, Stirpe F, Parente A. Sequence determination of lychnin, a type 1 ribosome-inactivating protein from Lychnis chalcedonica seeds. Biol Chem 2006; 387:1261-6. [PMID: 16972795 DOI: 10.1515/bc.2006.156] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The complete amino acid sequence of lychnin, a type 1 ribosome-inactivating protein (RIP) isolated from Lychnis chalcedonica seeds, has been determined by automated Edman degradation and ESI-QTOF mass spectrometry. Lychnin consists of 234 amino acid residues with a molecular mass of 26 131.14 Da. All amino acid residues involved in the formation of the RIP active site (Tyr69, Tyr119, Glu170, Arg173 and Trp203) are fully conserved. Furthermore, a fast MALDI-TOF experiment showed that two out of three cysteinyl residues (Cys32 and Cys115) form a disulfide bridge, while Cys214 is in the thiol form, which makes it suitable for linking carrier molecules to generate immunotoxins and other conjugates.
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Affiliation(s)
- Angela Chambery
- Dipartimento di Scienze della Vita, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta, Italy
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