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Shin MC, Zhang J, David AE, Trommer WE, Kwon YM, Min KA, Kim JH, Yang VC. Chemically and biologically synthesized CPP-modified gelonin for enhanced anti-tumor activity. J Control Release 2013; 172:169-178. [PMID: 23973813 DOI: 10.1016/j.jconrel.2013.08.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 12/15/2022]
Abstract
The ineffectiveness of small molecule drugs against cancer has generated significant interest in more potent macromolecular agents. Gelonin, a plant-derived toxin that inhibits protein translation, has attracted much attention in this regard. Due to its inability to internalize into cells, however, gelonin exerts only limited tumoricidal effect. To overcome this cell membrane barrier, we modified gelonin, via both chemical conjugation and genetic recombination methods, with low molecular weight protamine (LMWP), a cell-penetrating peptide (CPP) which was shown to efficiently ferry various cargoes into cells. Results confirmed that gelonin-LMWP chemical conjugate (cG-L) and recombinant gelonin-LMWP chimera (rG-L) possessed N-glycosidase activity equivalent to that of unmodified recombinant gelonin (rGel); however, unlike rGel, both gelonin-LMWPs were able to internalize into cells. Cytotoxicity studies further demonstrated that cG-L and rG-L exhibited significantly improved tumoricidal effects, with IC50 values being 120-fold lower than that of rGel. Moreover, when tested against a CT26 s.c. xenograft tumor mouse model, significant inhibition of tumor growth was observed with rG-L doses as low as 2 μg/tumor, while no detectable therapeutic effects were seen with rGel at 10-fold higher doses. Overall, this study demonstrated the potential of utilizing CPP-modified gelonin as a highly potent anticancer drug to overcome limitations of current chemotherapeutic agents.
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Affiliation(s)
- Meong Cheol Shin
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Jian Zhang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Allan E David
- Department of Chemical Engineering, Auburn University, Auburn, AL 36849, USA
| | - Wolfgang E Trommer
- Department of Chemistry, TU Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, Germany
| | - Young Min Kwon
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 S. University Dr., Ft. Lauderdale, FL 33328, USA
| | - Kyoung Ah Min
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Jin H Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA
| | - Victor C Yang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China; Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, 48109, USA.
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Abstract
Therapeutic agents capable of targeting tumor cells present as established tumors and micrometastases have already demonstrated their potential in clinical trials. Immunotoxins targeting hematological malignancies and solid tumors have additionally demonstrated excellent clinical activity. This review focuses on our design and characterization studies of constructs composed of recombinant gelonin toxin fused to either growth factors or single-chain antibodies targeting solid tumor cells, tumor vasculature or hematological malignancies. These agents demonstrate cytotoxicity at nanomolar or sub-nanomolar levels. All of these constructs display impressive selectivity and specificity for antigen-bearing target cells in vitro and in vivo and are excellent clinical trial candidates.
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Abstract
BACKGROUND Ligand targeted therapy (LTT) is a powerful pharmaceutical strategy to achieve selective drug delivery to pathological cells, for both therapeutic and diagnostic purposes, with the advantage of limited side effects and toxicity. This active drug targeting approach is based on the discovery that there are receptors overexpressed on pathological cells, compared to their expression in normal tissues. PURPOSE The purpose of this article is to review recently published data on LTT with applications, both in the field of cancer therapy and other diseases. Moreover, data on LTT exploiting receptors overexpressed at cytoplasmatic level are also reviewed. METHODS Data were deduced from Medline (PubMed) and SciFinder and their selections were made with preference to papers where the most relevant receptors were involved. RESULTS Several groups have reported improved delivery of targeted nanocarriers, as compared to nontargeted ones, to pathological cells. LTT offers several advantages, but there are also limitations in the development of this strategy. Moreover, LTT have shown encouraging results in in vitro and in animal models in vivo; hence their clinical potential awaits investigation. CONCLUSION Recent studies highlight that the ligand density plays an important role in targeting efficacy. Furthermore, LTT applications in diseases different from cancer and those exploiting receptors overexpressed at cytoplasmatic level are growing.
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Dosio F, Brusa P, Cattel L. Immunotoxins and anticancer drug conjugate assemblies: the role of the linkage between components. Toxins (Basel) 2011; 3:848-83. [PMID: 22069744 PMCID: PMC3202854 DOI: 10.3390/toxins3070848] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/02/2011] [Accepted: 07/06/2011] [Indexed: 12/02/2022] Open
Abstract
Immunotoxins and antibody-drug conjugates are protein-based drugs combining a target-specific binding domain with a cytotoxic domain. Such compounds are potentially therapeutic against diseases including cancer, and several clinical trials have shown encouraging results. Although the targeted elimination of malignant cells is an elegant concept, there are numerous practical challenges that limit conjugates’ therapeutic use, including inefficient cellular uptake, low cytotoxicity, and off-target effects. During the preparation of immunoconjugates by chemical synthesis, the choice of the hinge component joining the two building blocks is of paramount importance: the conjugate must remain stable in vivo but must afford efficient release of the toxic moiety when the target is reached. Vast efforts have been made, and the present article reviews strategies employed in developing immunoconjugates, focusing on the evolution of chemical linkers.
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Affiliation(s)
- Franco Dosio
- Department of Drug Science and Technology, University of Torino, Torino 10125, Italy.
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6
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Muskotál A, Kokol V. CE detection of N-(3-dimethylaminopropyl)-N-carbodiimide/N-hydroxysuccinimide-coupled proteins after homo- and hetero-crosslinking reactions. Electrophoresis 2010; 31:1097-100. [PMID: 20166141 DOI: 10.1002/elps.200900525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein-protein conjugates formed by carbodiimide crosslinking reactions have been analyzed for the first time using CE. Lysozyme and BSA were chosen as model proteins to study the efficacy of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide and N-hydroxysuccinimide as crosslinkers. Detection of the molecular mass increase was checked by SDS-PAGE. Commercially available, PVA-coated capillaries showed appropriate selection, while phospho-deactivated and dynamic PVA-coated capillaries did not give suitable resolution. CE was found to be an efficient tool to characterize homo- (lysozyme-lysozyme) and hetero- (lysozyme-BSA) protein coupling by suitable variations of electrophoretic mobilities.
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Affiliation(s)
- Adél Muskotál
- Institute of Engineering Materials and Design, Faculty of Mechanical Engineering, University of Maribor, Maribor, Slovenia
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8
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Safi S, Asfari Z, Hagège A. Characterization of protein conjugates using capillary electrophoresis. J Chromatogr A 2007; 1173:159-64. [PMID: 17964582 DOI: 10.1016/j.chroma.2007.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 10/04/2007] [Accepted: 10/08/2007] [Indexed: 10/22/2022]
Abstract
With the aim of generating antibodies, a calix[4]arene-crown-6 was coupled to bovine serum albumin. For that purpose, a complete procedure to optimize and characterize the coupling of hydrophobic haptens based on capillary electrophoresis (CE) was developed. We demonstrated the existence of a polynomial relationship between the electrophoretic mobility (mu(ep)) and the hapten density. This correlation was used not only to study the coupling reaction in terms of optimization and kinetics but also to determine the average coupling molar ratio of any given conjugate. An estimation of the heterogeneity of these conjugates by simulation of experimental peaks was also proposed.
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Affiliation(s)
- Samir Safi
- Laboratoire de Chimie Analytique et Minérale, IPHC-DSA (UMR 7178), ULP, CNRS, ECPM, 25 rue Becquerel, F-67087 Strasbourg Cedex, France
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9
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El-Sayed MEH, Hoffman AS, Stayton PS. Rational design of composition and activity correlations for pH-responsive and glutathione-reactive polymer therapeutics. J Control Release 2005; 104:417-27. [PMID: 15984055 DOI: 10.1016/j.jconrel.2005.01.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Limited cytoplasmic delivery of enzyme-susceptible drugs remains a significant challenge facing the development of protein and nucleic acid therapies that act in intracellular compartments. "Smart" pH-responsive, membrane-destabilizing polymers present a new approach to shuttling therapeutic molecules past the endosomal membrane and into the cytoplasm of targeted cells. This report describes the use of a functionalized monomer, pyridyl disulfide acrylate (PDSA), to develop pH-responsive, membrane-destabilizing, and glutathione-reactive polymers by copolymerization with several pH-responsive and hydrophobic monomers. The activity of the carriers is described as a function of (a) increasing the length of the hydrophobic alkyl group substituted onto the pH-responsive monomer and (b) the incorporation of a hydrophobic monomer such as butyl acrylate (BA) on the pH sensitivity and membrane-destabilizing activity of new polymer compositions. The membrane-destabilizing activity of different polymer compositions was evaluated as a function of pH and polymer concentration using the red blood cell (RBC) hemolysis assay. Hemolysis results show that the increase in the hydrophobic character of the polymer backbone results in a shift in the pH sensitivities and an increase in the membrane-destabilizing activity. Results show that the observed hemolytic activities and pH sensitivity profiles could be designed across a range that matches the properties needed for enhancing the cytoplasmic delivery of macromolecular therapeutic.
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Affiliation(s)
- Mohamed E H El-Sayed
- University of Washington, Department of Bioengineering, Box: 352255, Seattle, WA 98195-2255, USA
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El-Sayed MEH, Hoffman AS, Stayton PS. Rational design of composition and activity correlations for pH-sensitive and glutathione-reactive polymer therapeutics. J Control Release 2005; 101:47-58. [PMID: 15588893 DOI: 10.1016/j.jconrel.2004.08.032] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Accepted: 08/26/2004] [Indexed: 11/24/2022]
Abstract
Limited cytoplasmic delivery of enzyme-susceptible drugs remains a significant challenge facing the development of protein and nucleic acid therapies that act in intracellular compartments. "Smart" pH-sensitive, membrane-destabilizing polymers present an attractive approach to shuttle therapeutic molecules past the endosomal membrane and into the cytoplasm of targeted cells. This report describes the use of a new functionalized monomer, pyridyl disulfide acrylate (PDSA), to develop pH-sensitive, membrane-destabilizing, and glutathione-reactive polymers by copolymerization with several pH-sensitive and hydrophobic monomers. The activity of the carriers is described as a function of (a) the influence of increasing the length of the hydrophobic alkyl group substituted onto the pH-sensitive monomer and (b) of the effect of incorporating a hydrophobic monomer such as butyl acrylate (BA) on the pH sensitivity and membrane-destabilizing activity of new polymer compositions. The membrane-destabilizing activity of different polymer compositions was evaluated as a function of pH and polymer concentration using the red blood cells (RBC) hemolysis assay. Hemolysis results show that the increase in the hydrophobic character of polymer backbone results in a shift in the pH sensitivity profile and an increase in the membrane-destabilizing activity. Results show that the observed hemolytic activities and pH sensitivity profiles could be designed across a range that matches the properties needed for drug carriers to enhance the cytoplasmic delivery of therapeutic cargos.
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Affiliation(s)
- Mohamed E H El-Sayed
- University of Washington, Department of Bioengineering, Box: 352255, AERL 338, Seattle, WA 98195-2255, USA
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Firer MA, Laptev R, Kasatkin I, Trombka D. Specific destruction of hybridoma cells by antigen-toxin conjugates demonstrate an efficient strategy for targeted drug therapy in leukemias of the B cell lineage. Leuk Lymphoma 2003; 44:681-9. [PMID: 12769346 DOI: 10.1080/1042819031000063381] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Many types of leukemia including multiple myeloma remain essentially incurable despite recent developments in immuno- and chemotherapy. The effectiveness of these therapies might be greatly enhanced by targeting cell surface proteins unique to the malignant clone, which for leukemias of the B cell lineage means clonotypic surface immunoglobulin (sIg). As this immunoglobulin (Ig) is necessarily epitope specific, we are developing ligand-toxin conjugates (LTCs) as a strategy for delivering toxins and other drugs to clonotypic tumor cells. Here we report in vitro studies that illustrate the effectiveness of this approach. LTC comprising the DNP hapten conjugated to ricin A toxin (DNP-RTA) were shown to specifically and effectively kill anti-DNP secreting murine hybridoma (U7.6) cells but not other hybridoma cells (1B12), a murine erythroleukemia cell line (Friend's Leukemia or) normal mouse spleen cells. In addition to direct toxicity, LTC treatment negatively affected the growth characteristics of the few surviving cells as reflected in decreased growth index and an increase in growth inhibition over 72 h post treatment. Interestingly, U7.6 cells that survived one or two LD90 dose(s) of LTC showed no alteration in their dose response to a subsequent attack of LTC indicating that this treatment strategy may not induce drug resistance. These data suggest that LTC therapy may be a new and effective strategy for specific destruction of tumor cells such as myeloma plasma cells and could be extended to other tumors where clonotypic receptors can be identified.
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Affiliation(s)
- Michael A Firer
- Immunology Laboratory, Dept. Chemical Engineering and Biotechnology, College Judea and Samaria, P.O. Box 3, Ariel 44837 Israel.
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12
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Abstract
The potential of targeted delivery of chemotherapeutic drugs for the treatment of cancer has not yet been realized owing to the difficulty of delivering therapeutic concentrations to the target site. While in vivo studies in animal tumor models have produced very encouraging results, clinical studies with antibody-drug conjugates have been less successful. This paper will review the current status of the targeted delivery approach and analyze some of the reasons for the lack of success so far. Starting with a historical perspective, this review will end with a description of newer, more potent and specific antibody-drug conjugates, which behave like tumor-activated prodrugs that may yet fulfil the promise of the targeted delivery approach for the treatment of cancer.
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