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Komel T, Bosnjak M, Sersa G, Cemazar M. Expression of GFP and DsRed fluorescent proteins after gene electrotransfer of tumour cells in vitro. Bioelectrochemistry 2023; 153:108490. [PMID: 37356264 DOI: 10.1016/j.bioelechem.2023.108490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 06/27/2023]
Abstract
Fluorescent reporter genes are widely used to study the transfection of various types of primary cells and cell lines. The aim of our research was to investigate the expression dynamics of GFP and DsRed reporter genes individually and combined after gene electrotransfer of plasmids with two different electroporation protocols in B16F10 and CT26 cells in vitro. The cytotoxicity after gene electrotransfer of both plasmids was first determined. Second, the intensity of fluorescence and the percentage of cells transfected with both plasmids individually and in combination were monitored in real time. The results show that the percentage of viability after gene electrotransfer of plasmids using the EP2 pulses was significantly higher compared to the EP1 pulses. In contrast, the percentage of transfected cells and fluorescence intensity were higher after gene electrotransfer with the EP1 pulse protocol. Moreover, the percentage of transfected cells was higher and started earlier in the B16F10 cell line than in the CT26 cell line. However, fluorescence intensity was higher in CT26 cells. Co-expression of fluorescent proteins was achieved only in a small number of cells. In conclusion, this study elucidated some of the dynamics of reporter gene expression in cancer cell lines after gene electrotransfer.
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Affiliation(s)
- Tilen Komel
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Medicine, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Masa Bosnjak
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia
| | - Gregor Sersa
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, SI - 1000 Ljubljana, Slovenia
| | - Maja Cemazar
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Primorska, Faculty of Health Sciences, Polje 42, SI - 6310 Izola, Slovenia.
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2
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Komel T, Omerzel M, Kamensek U, Znidar K, Lampreht Tratar U, Kranjc Brezar S, Dolinar K, Pirkmajer S, Sersa G, Cemazar M. Gene Immunotherapy of Colon Carcinoma with IL-2 and IL-12 Using Gene Electrotransfer. Int J Mol Sci 2023; 24:12900. [PMID: 37629081 PMCID: PMC10454179 DOI: 10.3390/ijms241612900] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/12/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Gene immunotherapy has become an important approach in the treatment of cancer. One example is the introduction of genes encoding immunostimulatory cytokines, such as interleukin 2 and interleukin 12, which stimulate immune cells in tumours. The aim of our study was to determine the effects of gene electrotransfer of plasmids encoding interleukin 2 and interleukin 12 individually and in combination in the CT26 murine colon carcinoma cell line in mice. In the in vitro experiment, the pulse protocol that resulted in the highest expression of IL-2 and IL-12 mRNA and proteins was used for the in vivo part. In vivo, tumour growth delay and also complete response were observed in the group treated with the plasmid combination. Compared to the control group, the highest levels of various immunostimulatory cytokines and increased immune infiltration were observed in the combination group. Long-term anti-tumour immunity was observed in the combination group after tumour re-challenge. In conclusion, our combination therapy efficiently eradicated CT26 colon carcinoma in mice and also generated strong anti-tumour immune memory.
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Affiliation(s)
- Tilen Komel
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Masa Omerzel
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
| | - Urska Kamensek
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
| | - Katarina Znidar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
| | - Ursa Lampreht Tratar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
| | - Simona Kranjc Brezar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
| | - Klemen Dolinar
- Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia; (K.D.); (S.P.)
| | - Sergej Pirkmajer
- Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia; (K.D.); (S.P.)
| | - Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, SI-1000 Ljubljana, Slovenia
| | - Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia; (T.K.); (M.O.); (U.K.); (K.Z.); (U.L.T.); (S.K.B.); (G.S.)
- Faculty of Health Sciences, University of Primorska, Polje 42, SI-6310 Izola, Slovenia
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3
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Sales Conniff A, Tur J, Kohena K, Zhang M, Gibbons J, Heller LC. Transcriptomic Analysis of the Acute Skeletal Muscle Effects after Intramuscular DNA Electroporation Reveals Inflammatory Signaling. Vaccines (Basel) 2022; 10:vaccines10122037. [PMID: 36560447 PMCID: PMC9786673 DOI: 10.3390/vaccines10122037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022] Open
Abstract
Skeletal muscle is a promising tissue for therapeutic gene delivery because it is highly vascularized, accessible, and capable of synthesizing protein for therapies or vaccines. The application of electric pulses (electroporation) enhances plasmid DNA delivery and expression by increasing membrane permeability. Four hours after plasmid electroporation, we evaluated acute gene and protein expression changes in mouse skeletal muscle to identify regulated genes and genetic pathways. RNA sequencing followed by functional annotation was used to evaluate differentially expressed mRNAs. Our data highlighted immune signaling pathways that may influence the effectiveness of DNA electroporation. Cytokine and chemokine protein levels in muscle lysates revealed the upregulation of a subset of inflammatory proteins and confirmed the RNA sequencing analysis. Several regulated DNA-specific pattern recognition receptor mRNAs were also detected. Identifying unique molecular changes in the muscle will facilitate a better understanding of the underlying molecular mechanisms and the development of safety biomarkers and novel strategies to improve skeletal muscle targeted gene therapy.
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Affiliation(s)
- Amanda Sales Conniff
- Department of Medical Engineering, University of South Florida, Tampa, FL 33612, USA
| | - Jared Tur
- Department of Medical Engineering, University of South Florida, Tampa, FL 33612, USA
| | - Kristopher Kohena
- Department of Medical Engineering, University of South Florida, Tampa, FL 33612, USA
| | - Min Zhang
- USF Genomics Core, University of South Florida, Tampa, FL 33612, USA
| | - Justin Gibbons
- USF Omics Hub, University of South Florida, Tampa, FL 33612, USA
| | - Loree C. Heller
- Department of Medical Engineering, University of South Florida, Tampa, FL 33612, USA
- Correspondence: ; Tel.: +1-813-974-4637
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Bhandary M, Sales Conniff A, Miranda K, Heller LC. Acute Effects of Intratumor DNA Electrotransfer. Pharmaceutics 2022; 14:pharmaceutics14102097. [PMID: 36297532 PMCID: PMC9611921 DOI: 10.3390/pharmaceutics14102097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/14/2022] Open
Abstract
Intratumor therapeutic DNA electroporation or electrotransfer is in clinical trials in the United States and is under development in many other countries. Acute changes in endogenous gene expression in response to DNA or to pulse application may significantly modulate the therapeutic efficacy of the expressed proteins. Oligonucleotide arrays were used in this study to quantify changes in mRNA expression in B16-F10 mouse melanoma tumors four hours after DNA electrotransfer. The data were subjected to the DAVID v6.8 web server for functional annotation to reveal regulated genes and genetic pathways. Gene ontology analysis revealed several molecular functions related to cytoskeletal remodeling and inflammatory signaling. In B16-F10 cells, F-actin remodeling was confirmed by phalloidin staining in cells that received pulse application alone or in the presence of DNA. Chemokine secretion was confirmed in cells receiving DNA electrotransfer. These results indicate that pulse application alone or in the presence of DNA may modulate the therapeutic efficacy of therapeutic DNA electrotransfer.
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In vitro and in vivo correlation of skin and cellular responses to nucleic acid delivery. Biomed Pharmacother 2022; 150:113088. [PMID: 35658241 PMCID: PMC10010056 DOI: 10.1016/j.biopha.2022.113088] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/01/2022] [Accepted: 05/04/2022] [Indexed: 11/21/2022] Open
Abstract
Skin, the largest organ in the body, provides a passive physical barrier against infection and contains elements of the innate and adaptive immune systems. Skin consists of various cells, including keratinocytes, fibroblasts, endothelial cells and immune cells. This diversity of cell types could be important to gene therapies because DNA transfection could elicit different responses in different cell types. Previously, we observed the upregulation and activation of cytosolic DNA sensing pathways in several non-tumor and tumor cell types as well in tumors after the electroporation (electrotransfer) of plasmid DNA (pDNA). Based on this research and the innate immunogenicity of skin, we correlated the effects of pDNA electrotransfer to fibroblasts and keratinocytes to mouse skin using reverse transcription real-time PCR (RT-qPCR) and several types of protein quantification. After pDNA electrotransfer, the mRNAs of the putative DNA sensors DEAD (AspGlu-Ala-Asp) box polypeptide 60 (Ddx60), absent in melanoma 2 (Aim2), Z-DNA binding protein 1 (Zbp1), interferon activated gene 202 (Ifi202), and interferon-inducible protein 204 (Ifi204) were upregulated in keratinocytes, while Ddx60, Zbp1 and Ifi204 were upregulated in fibroblasts. Increased levels of the mRNAs and proteins of several cytokines and chemokines were detected and varied based on cell type. Mouse skin experiments in vivo confirmed our in vitro results with increased expression of putative DNA sensor mRNAs and of the mRNAs and proteins of several cytokines and chemokines. Finally, with immunofluorescent staining, we demonstrated that skin keratinocytes, fibroblasts and macrophages contribute to the immune response observed after pDNA electrotransfer.
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Komel T, Bosnjak M, Kranjc Brezar S, De Robertis M, Mastrodonato M, Scillitani G, Pesole G, Signori E, Sersa G, Cemazar M. Gene electrotransfer of IL-2 and IL-12 plasmids effectively eradicated murine B16.F10 melanoma. Bioelectrochemistry 2021; 141:107843. [PMID: 34139572 DOI: 10.1016/j.bioelechem.2021.107843] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 05/05/2021] [Accepted: 05/13/2021] [Indexed: 12/18/2022]
Abstract
Gene therapy has become an important approach for treating cancer, and electroporation represents a technology for introducing therapeutic genes into a cell. An example of cancer gene therapy relying on gene electrotransfer is the use of immunomodulatory cytokines, such as interleukin 2 (IL-2) and 12 (IL-12), which directly stimulate immune cells at the tumour site. The aim of our study was to determine the effects of gene electrotransfer with two plasmids encoding IL-2 and IL-12 in vitro and in vivo. Two different pulse protocols, known as EP1 (600 V/cm, 5 ms, 1 Hz, 8 pulses) and EP2 (1300 V/cm, 100 µs, 1 Hz, 8 pulses), were assessed in vitro for application in subsequent in vivo experiments. In the in vivo experiment, gene electrotransfer of pIL-2 and pIL-12 using the EP1 protocol was performed in B16.F10 murine melanoma. Combined treatment of tumours using pIL2 and pIL12 induced significant tumour growth delay and 71% complete tumour regression. Furthermore, in tumours coexpressing IL-2 and IL-12, increased accumulation of dendritic cells and M1 macrophages was obtained along with the activation of proinflammatory signals, resulting in CD4 + and CD8 + T-lymphocyte recruitment and immune memory development in the mice. In conclusion, we demonstrated high antitumour efficacy of combined IL-2 and IL-12 gene electrotransfer protocols in low-immunogenicity murine B16.F10 melanoma.
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Affiliation(s)
- T Komel
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Medicine, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - M Bosnjak
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia
| | - S Kranjc Brezar
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Medicine, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - M De Robertis
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Via Orabona 4, 70126 Bari, Italy
| | - M Mastrodonato
- Department of Biology, University of Bari, Via Orabona 4, 70126 Bari, Italy
| | - G Scillitani
- Department of Biology, University of Bari, Via Orabona 4, 70126 Bari, Italy
| | - G Pesole
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Via Orabona 4, 70126 Bari, Italy; National Research Council-Institute of Biomembrane, Bioenergetics, and Molecular Biotechnology (CNR-IBIOM), Via Amendola 122 O, 70126, Bari, Italy
| | - E Signori
- National Research Council-Institute of Translational Pharmacology (CNR-IFT), Via Fosso del Cavaliere 100, Rome, Italy
| | - G Sersa
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, SI - 1000 Ljubljana, Slovenia
| | - M Cemazar
- Institute of Oncology Ljubljana, Department of Experimental Oncology, Zaloska 2, SI-1000 Ljubljana, Slovenia; University of Primorska, Faculty of Health Sciences, Polje 42, SI - 6310 Izola, Slovenia.
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Growth environment influences B16.F10 mouse melanoma cell response to gene electrotransfer. Bioelectrochemistry 2021; 140:107827. [PMID: 33971375 DOI: 10.1016/j.bioelechem.2021.107827] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 04/15/2021] [Accepted: 04/20/2021] [Indexed: 01/21/2023]
Abstract
We developed and characterized a 3D collagen hydrogel model for B16.F10 melanoma tumors. Cells in this 3D environment exhibited lower proliferation than cells in the conventional 2D culture environment. Interestingly, the basal expression levels of several genes varied when compared to conventionally grown cells. In each growth environment, a significant number of melanoma cells were transfected by plasmid electroporation (electrotransfer), although expression could only be ascertained on the surface of the 3D constructs. Cellular responses to plasmid entry as demonstrated by pro-inflammatory cytokine and chemokine upregulation varied based on the growth environment, as did the mRNA levels of several putative DNA-specific pattern recognition receptors (DNA sensors). Unexpectedly, when plasmid DNA was delivered while cells where attached in the 2D or 3D environments, the mRNAs of the DNA sensor p204 and the inflammatory mediator TNFα were regulated in cells receiving pulses only. However, we were unable to confirm coordinate upregulation of TNFα and p204 proteins. This study confirms that cell responses differ significantly based on their environment, and demonstrates the difficulty of extending experimental observations between cell environments.
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Heller R, Shi G. Controlled Delivery of Plasmid DNA to Melanoma Tumors by Gene Electrotransfer. Methods Mol Biol 2021; 2265:635-644. [PMID: 33704744 DOI: 10.1007/978-1-0716-1205-7_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Gene electrotransfer (GET) is a reliable and effective physical method for in vivo delivery of plasmid DNA (pDNA). Several preclinical and clinical studies have utilized GET to deliver plasmids encoding immune stimulating genes for treatment of melanoma and other tumor types. Intratumor delivery of plasmids encoding cytokines directly to tumors can induce not only a local immune response, but a systemic one as well. To obtain an effective immune response, it is critical to achieve the appropriate expression pattern of the delivered transgene. Expression pattern (levels and kinetics) can be modified by manipulating the electrotransfer parameters. These parameters include the tissue target and the electric pulse parameters of pulse width, electric field, and pulse number. We have found that to induce a robust immune response, we needed only low to moderately elevated expression levels compared to controls. When developing a therapeutic protocol, it is important to establish what expression profile will enable the appropriate response. In this chapter we describe how to determine the appropriate GET protocol to achieve the expression profile that can result in the desired clinical response.
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Affiliation(s)
- Richard Heller
- Department of Medical Engineering, Colleges of Medicine and Engineering, University of South Florida, Tampa, FL, USA.
| | - Guilan Shi
- Department of Medical Engineering, Colleges of Medicine and Engineering, University of South Florida, Tampa, FL, USA
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Semenova N, Bosnjak M, Markelc B, Znidar K, Cemazar M, Heller L. Multiple cytosolic DNA sensors bind plasmid DNA after transfection. Nucleic Acids Res 2019; 47:10235-10246. [PMID: 31495892 PMCID: PMC6821305 DOI: 10.1093/nar/gkz768] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 08/22/2019] [Indexed: 12/31/2022] Open
Abstract
Mammalian cells express a variety of nucleic acid sensors as one of the first lines of defense against infection. Despite extensive progress in the study of sensor signaling pathways during the last decade, the detailed mechanisms remain unclear. In our previous studies, we reported increased type I interferon expression and the upregulation of several proposed cytosolic DNA sensors after transfection of several tumor cell types with plasmid DNA (pDNA). In the present study, we sought to reveal the early events in the cytosolic sensing of this nucleic acid in a myoblast cell line. We demonstrated that DNA-dependent activator of interferon regulatory factors/Z-DNA binding protein 1 (DAI/ZBP1) bound plasmid DNA in the cytosol within 15 minutes of transfection and at consistent levels for 4 h. Interferon activated gene 204 protein (p204) and DEAH box helicase 9 (DHX9) also bound pDNA, peaking 15 and 30 min respectively. Plasmid DNA was not detectably bound by DEAD box helicase 60 (DDX60) protein, despite a similar level of mRNA upregulation to DAI/ZBP1, or by cyclic GMP-AMP synthase (cGAS), despite its presence in the cell cytosol. Taken together, these results indicate several DNA sensors may participate and cooperate in the complex process of cytosolic DNA sensing.
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Affiliation(s)
- Nina Semenova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Masa Bosnjak
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Bostjan Markelc
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Katarina Znidar
- Faculty of Health Sciences, University of Primorska, Izola, Slovenia
| | - Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.,Faculty of Health Sciences, University of Primorska, Izola, Slovenia
| | - Loree Heller
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA.,School of Medical Diagnostic and Translational Sciences, Old Dominion University, Norfolk, VA, USA
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Liu Z, Zhao L, Zhang Q, Huo N, Shi X, Li L, Jia L, Lu Y, Peng Y, Song Y. Proteomics-Based Mechanistic Investigation of Escherichia coli Inactivation by Pulsed Electric Field. Front Microbiol 2019; 10:2644. [PMID: 31781086 PMCID: PMC6857472 DOI: 10.3389/fmicb.2019.02644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/30/2019] [Indexed: 11/21/2022] Open
Abstract
The pulsed electric field (PEF) technology has been widely applied to inactivate pathogenic bacteria in food products. Though irreversible pore formation and membrane disruption is considered to be the main contributing factor to PEF's sterilizing effects, the exact molecular mechanisms remain poorly understood. In this study, by using mass spectrometry (MS)-based label-free quantitative proteomic analysis, we compared the protein profiles of PEF-treated and untreated Escherichia coli. We identified a total of 175 differentially expressed proteins, including 52 candidates that were only detected in at least two of the three samples in one experiment group but not in the other group. Functional analysis revealed that the differential proteins were primarily involved in the regulation of cell membrane composition and integrity, stress response, as well as various metabolic processes. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was conducted on the genes of selected differential proteins at varying PEF intensities, which were known to result in different cell killing levels. The qRT-PCR data confirmed that the proteomic results could be reliably used for further data interpretation, and that the changes in the expression levels of the differential candidates were, to a large extent, caused directly by the PEF treatment. The findings of the current study offered valuable insight into PEF-induced cell inactivation.
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Affiliation(s)
- Zhenyu Liu
- Information Science and Engineering College, Shanxi Agricultural University, Jinzhong, China
| | - Lingying Zhao
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, Columbus, OH, United States
| | - Qin Zhang
- Life Science College, Shanxi Agricultural University, Jinzhong, China
| | - Nan Huo
- Life Science College, Shanxi Agricultural University, Jinzhong, China
| | - Xiaojing Shi
- Life Science College, Shanxi Agricultural University, Jinzhong, China
| | - Linwei Li
- Information Science and Engineering College, Shanxi Agricultural University, Jinzhong, China
| | - Liyan Jia
- College of Food Science and Engineering, Shanxi Agricultural University, Jinzhong, China
| | - Yuanyuan Lu
- Life Science College, Shanxi Agricultural University, Jinzhong, China
| | - Yong Peng
- Shanghai Applied Protein Technology Co., Ltd., Shanghai, China
| | - Yanbo Song
- Life Science College, Shanxi Agricultural University, Jinzhong, China
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Znidar K, Bosnjak M, Jesenko T, Heller LC, Cemazar M. Upregulation of DNA Sensors in B16.F10 Melanoma Spheroid Cells After Electrotransfer of pDNA. Technol Cancer Res Treat 2018; 17:1533033818780088. [PMID: 29879868 PMCID: PMC6009088 DOI: 10.1177/1533033818780088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Increased expression of cytosolic DNA sensors, a category of pattern recognition receptor, after control plasmid DNA electrotransfer was observed in our previous studies on B16.F10 murine melanoma cells. This expression was correlated with the upregulation of proinflammatory cytokines and chemokines and was associated with cell death. Here, we expanded our research to include the influence of features of cells in a 3-dimensional environment, which better represents the tumors' organization in vivo. Our results show that lower number of cells were transfected in spheroids compared to 2-dimensional cultures, that growth was delayed after electroporation alone or after electrotransfer of plasmid DNA, and that DNA sensors DDX60, DAI/ZBP1, and p204 were upregulated 4 hours and 24 hours after electrotransfer of plasmid DNA. Moreover, the cytokines interferon β and tumor necrosis factor α were also upregulated but only 4 hours after electrotransfer of plasmid DNA. Thus, our results confirm the results obtained in 2-dimensional cell cultures demonstrating that electrotransfer of plasmid DNA to tumor cells in spheroids also upregulated cytosolic DNA sensors and cytokines.
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Affiliation(s)
- Katarina Znidar
- 1 Faculty of Health Sciences, University of Primorska, Koper, Slovenia
| | - Masa Bosnjak
- 2 Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Tanja Jesenko
- 2 Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Loree C Heller
- 3 Frank Reidy Research Center of Bioelectrics, Old Dominion University, Norfolk, VA, USA.,4 School of Medical Diagnostic and Translational Sciences, College of Health Sciences, Old Dominion, University, Norfolk, VA, USA
| | - Maja Cemazar
- 1 Faculty of Health Sciences, University of Primorska, Koper, Slovenia.,2 Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
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Tumor cell death after electrotransfer of plasmid DNA is associated with cytosolic DNA sensor upregulation. Oncotarget 2018; 9:18665-18681. [PMID: 29721152 PMCID: PMC5922346 DOI: 10.18632/oncotarget.24816] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 02/27/2018] [Indexed: 12/19/2022] Open
Abstract
Cytosolic DNA sensors are a subgroup of pattern recognition receptors (PRRs) and are activated by the abnormal presence of the DNA in the cytosol. Their activation leads to the upregulation of pro-inflammatory cytokines and chemokines and can also induce cell death. The presence of cytosolic DNA sensors and inflammatory cytokines in TS/A murine mammary adenocarcinoma and WEHI 164 fibrosarcoma cells was demonstrated using real time reverse transcription polymerase chain reaction (RT-PCR), western blotting and enzyme-linked immunosorbent assay (ELISA). After electrotransfer of plasmid DNA (pDNA) using two pulse protocols, the upregulation of DNA-depended activator of interferon regulatory factor or Z-DNA binding protein 1 (DAI/ZBP1), DEAD (Asp-Glu-Ala-Asp) box polypeptide 60 (DDX60) and interferon-inducible protein 204 (p204) mRNAs was observed in both tumor cell lines, but their expression was pulse protocol dependent. A decrease in cell survival was also observed; it was cell type, DNA concentration and pulse protocol dependent. Furthermore, the different protocols of electrotransfer led to different cell death outcomes, necrosis and apoptosis, as indicated by an annexin V and 7AAD assays. The obtained data provide new insights on the presence of cytosolic DNA sensors in tumor cells and the activation of different types of cells death after electrotransfer of pDNA. These observations have important implications on the planning of gene therapy or DNA vaccination protocols.
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Cytosolic DNA Sensor Upregulation Accompanies DNA Electrotransfer in B16.F10 Melanoma Cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 5:e322. [PMID: 27271988 PMCID: PMC5022127 DOI: 10.1038/mtna.2016.34] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 04/11/2016] [Indexed: 01/05/2023]
Abstract
In several preclinical tumor models, antitumor effects occur after intratumoral electroporation, also known as electrotransfer, of plasmid DNA devoid of a therapeutic gene. In mouse melanomas, these effects are preceded by significant elevation of several proinflammatory cytokines. These observations implicate the binding and activation of intracellular DNA-specific pattern recognition receptors or DNA sensors in response to DNA electrotransfer. In tumors, IFNβ mRNA and protein levels significantly increased. The mRNAs of several DNA sensors were detected, and DAI, DDX60, and p204 tended to be upregulated. These effects were accompanied with reduced tumor growth and increased tumor necrosis. In B16.F10 cells in culture, IFNβ mRNA and protein levels were significantly upregulated. The mRNAs for several DNA sensors were present in these cells; DNA-dependent activator of interferon regulatory factor (DAI), DEAD (Asp-Glu-Ala-Asp) box polypeptide 60 (DDX60), and p204 were significantly upregulated while DDX60 protein levels were coordinately upregulated. Upregulation of DNA sensors in tumors could be masked by the lower transfection efficiency compared to in vitro or to dilution by other tumor cell types. Mirroring the observation of tumor necrosis, cells underwent a significant DNA concentration-dependent decrease in proliferation and survival. Taken together, these results indicate that DNA electrotransfer may cause the upregulation of several intracellular DNA sensors in B16.F10 cells, inducing effects in vitro and potentially in vivo.
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Wei X, Shao B, He Z, Ye T, Luo M, Sang Y, Liang X, Wang W, Luo S, Yang S, Zhang S, Gong C, Gou M, Deng H, Zhao Y, Yang H, Deng S, Zhao C, Yang L, Qian Z, Li J, Sun X, Han J, Jiang C, Wu M, Zhang Z. Cationic nanocarriers induce cell necrosis through impairment of Na(+)/K(+)-ATPase and cause subsequent inflammatory response. Cell Res 2015; 25:237-53. [PMID: 25613571 PMCID: PMC4650577 DOI: 10.1038/cr.2015.9] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/18/2014] [Accepted: 10/20/2014] [Indexed: 12/15/2022] Open
Abstract
Nanocarriers with positive surface charges are known for their toxicity which has limited their clinical applications. The mechanism underlying their toxicity, such as the induction of inflammatory response, remains largely unknown. In the present study we found that injection of cationic nanocarriers, including cationic liposomes, PEI, and chitosan, led to the rapid appearance of necrotic cells. Cell necrosis induced by cationic nanocarriers is dependent on their positive surface charges, but does not require RIP1 and Mlkl. Instead, intracellular Na+ overload was found to accompany the cell death. Depletion of Na+ in culture medium or pretreatment of cells with the Na+/K+-ATPase cation-binding site inhibitor ouabain, protected cells from cell necrosis. Moreover, treatment with cationic nanocarriers inhibited Na+/K+-ATPase activity both in vitro and in vivo. The computational simulation showed that cationic carriers could interact with cation-binding site of Na+/K+-ATPase. Mice pretreated with a small dose of ouabain showed improved survival after injection of a lethal dose of cationic nanocarriers. Further analyses suggest that cell necrosis induced by cationic nanocarriers and the resulting leakage of mitochondrial DNA could trigger severe inflammation in vivo, which is mediated by a pathway involving TLR9 and MyD88 signaling. Taken together, our results reveal a novel mechanism whereby cationic nanocarriers induce acute cell necrosis through the interaction with Na+/K+-ATPase, with the subsequent exposure of mitochondrial damage-associated molecular patterns as a key event that mediates the inflammatory responses. Our study has important implications for evaluating the biocompatibility of nanocarriers and designing better and safer ones for drug delivery.
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Affiliation(s)
- Xiawei Wei
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Bin Shao
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Zhiyao He
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Tinghong Ye
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Min Luo
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Yaxiong Sang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Xiao Liang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Wei Wang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Shuntao Luo
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Shengyong Yang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Shuang Zhang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Changyang Gong
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Maling Gou
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Hongxing Deng
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Yinglan Zhao
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Hanshuo Yang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Senyi Deng
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Chengjian Zhao
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Li Yang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Zhiyong Qian
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Jiong Li
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Xun Sun
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Chengyu Jiang
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Department of Biochemistry and Molecular Biology, Peking Union Medical College, Beijing 100005, China
| | - Min Wu
- Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA
| | - Zhirong Zhang
- Key Laboratory of Drug Targeting of Ministry of Education, State Key Laboratory of Biotherapy/Collaborative Innovation Center, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan 610041, China
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Changing electrode orientation, but not pulse polarity, increases the efficacy of gene electrotransfer to tumors in vivo. Bioelectrochemistry 2014; 100:119-27. [DOI: 10.1016/j.bioelechem.2013.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 12/05/2013] [Accepted: 12/06/2013] [Indexed: 12/21/2022]
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Heller L, Todorovic V, Cemazar M. Electrotransfer of single-stranded or double-stranded DNA induces complete regression of palpable B16.F10 mouse melanomas. Cancer Gene Ther 2013; 20:695-700. [PMID: 24287723 PMCID: PMC3875131 DOI: 10.1038/cgt.2013.71] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/21/2013] [Accepted: 11/11/2013] [Indexed: 12/24/2022]
Abstract
Enhanced tumor delivery of plasmid DNA with electric pulses in vivo has been confirmed in many preclinical models. Intratumor electrotransfer of plasmids encoding therapeutic molecules has reached Phase II clinical trials. In multiple preclinical studies, a reduction in tumor growth, increased survival or complete tumor regression have been observed in control groups in which vector or backbone plasmid DNA electrotransfer was performed. This study explores factors that could produce this antitumor effect. The specific electrotransfer pulse protocol employed significantly potentiated the regression. Tumor regression was observed after delivery of single-stranded or double-stranded DNA with or without CpG motifs in both immunocompetent and immunodeficient mice, indicating the involvement of the innate immune system in response to DNA. In conclusion, this study demonstrated that the observed antitumor effects are not due to a single factor, but to a combination of factors.
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Affiliation(s)
- L Heller
- 1] Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA [2] School of Medical Diagnostic & Translational Sciences, College of Health Sciences, Old Dominion University, Norfolk, VA, USA
| | - V Todorovic
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - M Cemazar
- 1] Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia [2] University of Primorska, Faculty of Health Sciences, Izola, Slovenia
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Marrero B, Shirley S, Heller R. Delivery of interleukin-15 to B16 melanoma by electroporation leads to tumor regression and long-term survival. Technol Cancer Res Treat 2013; 13:551-60. [PMID: 24000979 PMCID: PMC4527479 DOI: 10.7785/tcrtexpress.2013.600252] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Electroporation (EP) is a method used to physically deliver therapeutic molecules such as plasmid DNA directly to tissues. It has been used safely and successfully in clinical studies and preclinical cancer models to deliver genes to a variety of tissues. In cancer research cytokine therapy is emerging as a promising tool that can be used to boost the host response to tumor antigens. The delivery of cytokines as recombinant proteins can result in toxicity and other adverse effects; however the delivery of cytokine genes using EP has been shown to be safe and effective. Interleukin 15 (IL-15) is a cytokine that promotes the innate as well as the adaptive immune response to cancer cells and bacterial pathogens. In this study we used EP to deliver a human IL-15 plasmid (phIL-15) directly to tumors to examine its anti-cancer effects. B16.F10 melanoma tumors were induced in C57BL/6J mice and phIL-15 was delivered three times over the course of a week. Expression of the transgene, tumor volume, long-term survival and resistance to challenge were monitored in these animals. Delivery of IL-15 plasmid by EP resulted in increased IL-15 expression within the tumor compared to the injection only control. This expression peaked at 12 to 18 hours after the first delivery and was sustained at lower levels after the second and third deliveries. The delivery of the phIL-15 resulted in tumor regression, long-term survival and greater protection against tumor recurrence when cancer cells were reintroduced compared to control plasmid. From these results we can conclude that the delivery of IL-15 plasmid to tumors using EP is a promising avenue to investigate for its anti-tumor effects, however more work needs to be done to increase the stability of the gene once it is delivered and to elucidate the anti-tumor mechanism.
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Affiliation(s)
- Bernadette Marrero
- Department of Molecular Medicine, University of South Florida, Tampa, Florida 33613, USA.
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18
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Sin JI, Park JB, Lee IH, Park D, Choi YS, Choe J, Celis E. Intratumoral electroporation of IL-12 cDNA eradicates established melanomas by Trp2(180-188)-specific CD8+ CTLs in a perforin/granzyme-mediated and IFN-γ-dependent manner: application of Trp2(180-188) peptides. Cancer Immunol Immunother 2012; 61:1671-82. [PMID: 22382361 PMCID: PMC11028417 DOI: 10.1007/s00262-012-1214-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/27/2012] [Indexed: 01/05/2023]
Abstract
Intratumoral electroporation (IT-EP) with IL-12 cDNA (IT-EP/IL12) can lead to the eradication of established B16 melanoma tumors in mice. Here, we explore the immunological mechanism of the antitumor effects generated by this therapy. The results show that IT-EP/IL12 applied only once resulted in eradication in 70% animals with large established B16 tumors. Tumor eradication required the participation of CD8+ T cells, but not CD4+ T cells and NK cells. IT-EP/IL12 induced antigen-specific CD8+ T cell responses against the immunodominant Trp2(180-188) epitope and generated a systemic response, resulting in significant therapeutic effects against distal, untreated tumors. The therapeutic effect of IT-EP/IL12 was absent in perforin-deficient mice, indicating that tumor elimination occurred through conventional perforin/granzyme lysis by CTLs. Moreover, this therapy induced some degree of immunological memory that protected approximately one-third of the cured mice against a subsequent tumor challenge. Moreover, antitumor efficacy and long-term protection against B16 were significantly improved by concurrent Trp2 peptide immunization through more induction of Ag-specific CTL responses and more attraction of IFN-γ-expressing CD8+ T cells into tumor sites. The antitumor effect of IT-EP/IL12 required the participation of IFN-γ, which was shown to induce MHC class I expression on B16 cells and increase the lytic activity of the CD8+ CTL generated by IT-EP/IL12. The results from these animal studies may help in the development of IT-EP/IL12 for cancer patients.
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Affiliation(s)
- Jeong-Im Sin
- Department of Microbiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do 200-701, Korea.
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Markelc B, Tevz G, Cemazar M, Kranjc S, Lavrencak J, Zegura B, Teissie J, Sersa G. Muscle gene electrotransfer is increased by the antioxidant tempol in mice. Gene Ther 2011; 19:312-20. [PMID: 21716301 PMCID: PMC3298856 DOI: 10.1038/gt.2011.97] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Electropermeabilization (EP) is an effective method of gene transfer into different tissues. During EP, reactive oxygen species (ROS) are formed, which could affect transfection efficiency. The role of generated ROS and the role of antioxidants in electrotransfer in myoblasts in vitro and in Musculus tibialis cranialis in mice were, therefore, investigated. We demonstrate in the study that during EP of C2C12 myoblasts, ROS are generated on the surface of the cells, which do not induce long-term genomic DNA damage. Plasmid DNA for transfection (pEGFP-N1), which is present outside the cells during EP, neutralizes the generated ROS. The ROS generation is proportional to the amplitude of the electric pulses and can be scavenged by antioxidants, such as vitamin C or tempol. When antioxidants were used during gene electrotransfer, the transfection efficiency of C2C12 myoblasts was statistically significantly increased 1.6-fold with tempol. Also in vivo, the transfection efficiency of M. tibialis cranialis in mice was statistically significantly increased 1.4-fold by tempol. The study indicates that ROS are generated on cells during EP and can be scavenged by antioxidants. Specifically, tempol can be used to improve gene electrotransfer into the muscle and possibly also to other tissues.
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Affiliation(s)
- B Markelc
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
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Abstract
DNA-based vaccines, while highly immunogenic in mice, generate significantly weaker responses in primates. Therefore, current efforts are aimed at increasing their immunogenicity, which include optimizing the plasmid/gene, the vaccine formulation and method of delivery. For example, co-immunization with molecular adjuvants encoding an immunomodulatory protein has been shown to improve the antigen (Ag)-specific immune response. Thus, the incorporation of enhancing elements, such as these, may be particularly important in the influenza model in which high titered antibody (Ab) responses are critical for protection. In this regard, we compared the ability of plasmid-encoded high-mobility group box 1 protein (HMGB1), a novel cytokine in which we have previously mutated in order to increase DNA vaccine immunogenicity, with boost Ag-specific immune responses during DNA vaccination with influenza A/PR/8/34 nucleoprotein or the hemagglutinin of A novel H1N1/09. We show that the HMGB1 adjuvant is capable of enhancing adaptive effector and memory immune responses. Although Ag-specific antibodies were detected in all vaccinated animals, a greater neutralizing Ab response was associated with the HMGB1 adjuvant. Furthermore, these responses improved CD8 T+-cell effector and memory responses and provided protection against a lethal mucosal influenza A/PR/8/34 challenge. Thus, co-immunization with HMGB1 has strong in vivo adjuvant activity during the development of immunity against plasmid-encoded Ag.
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