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Tang H, Cai L, He X, Niu Z, Huang H, Hu W, Bian H, Huang H. Radiation-induced bystander effect and its clinical implications. Front Oncol 2023; 13:1124412. [PMID: 37091174 PMCID: PMC10113613 DOI: 10.3389/fonc.2023.1124412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
For many years, targeted DNA damage caused by radiation has been considered the main cause of various biological effects. Based on this paradigm, any small amount of radiation is harmful to the organism. Epidemiological studies of Japanese atomic bomb survivors have proposed the linear-non-threshold model as the dominant standard in the field of radiation protection. However, there is increasing evidence that the linear-non-threshold model is not fully applicable to the biological effects caused by low dose radiation, and theories related to low dose radiation require further investigation. In addition to the cell damage caused by direct exposure, non-targeted effects, which are sometimes referred to as bystander effects, abscopal effects, genetic instability, etc., are another kind of significant effect related to low dose radiation. An understanding of this phenomenon is crucial for both basic biomedical research and clinical application. This article reviews recent studies on the bystander effect and summarizes the key findings in the field. Additionally, it offers a cross-sectional comparison of bystander effects caused by various radiation sources in different cell types, as well as an in-depth analysis of studies on the potential biological mechanisms of bystander effects. This review aims to present valuable information and provide new insights on the bystander effect to enlighten both radiobiologists and clinical radiologists searching for new ways to improve clinical treatments.
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Affiliation(s)
- Haoyi Tang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Luwei Cai
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Xiangyang He
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Zihe Niu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Haitong Huang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Wentao Hu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
- *Correspondence: Hao Huang, ; Huahui Bian, ; Wentao Hu,
| | - Huahui Bian
- Nuclear and Radiation Incident Medical Emergency Office, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Hao Huang, ; Huahui Bian, ; Wentao Hu,
| | - Hao Huang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
- *Correspondence: Hao Huang, ; Huahui Bian, ; Wentao Hu,
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Pakniyat F, Nedaie HA, Mozdarani H, Mahmoudzadeh A, Salimi M, Griffin RJ, Gholami S. Enhanced response of radioresistant carcinoma cell line to heterogeneous dose distribution of grid; the role of high-dose bystander effect. Int J Radiat Biol 2020; 96:1585-1596. [PMID: 33074047 DOI: 10.1080/09553002.2020.1834163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE The classical dogma that restricted the radiation effect to the directly irradiated cells has been challenged by the bystander effect. This off-target phenomenon which was manifested in adjacent cells via signaling of fully exposed cells might be involved in high-dose Grid therapy as well. Here, an in-vitro study was performed to examine the possible extent of carcinoma cells response to the inhomogeneous dose distribution of Grid irradiation in the context of the bystander effect. MATERIALS AND METHODS Bystander effect was investigated in human carcinoma cell lines of HeLa and HN5 adjacent to those received high-dose Grid irradiation using 'medium transfer' and 'cell-to-cell contact' strategies. Based on the Grid peak-to-valley dose profile, medium transfer was exerted from 10 Gy uniformly exposed donors to 1.5 Gy uniformly irradiated recipients. Cell-contact bystander was evaluated after nonuniform dose distribution of 10 Gy Grid irradiation using cloning cylinders. GammaH2AX foci, micronucleus and clonogenic assays besides gene expression analysis were performed. RESULTS Various parameters (ɑ/β, D37, D50) extracted from survival curve which fitted to the Linear Quadratic model, verified more radioresistance of HN5. Survival fraction at 2 Gy (SF2) indicated as 0.42 ± 0.06 in HeLa and 0.5 ± 0.03 in HN5. The level of survival decrease, DNA damages and micronucleus of cells located in the Grid shielded areas (1.5 Gy cell-to-cell contact bystander cells) were significantly more than the values obtained from cells which were irradiated by merely uniform dose of 1.5 Gy. The gH2AX foci and micronuclei frequencies were enhanced in cell-contact bystander approximately more than 1.8 times. Relative expression of DNA damage repair pathway genes (Xrcc6 and H2afx) in bystander cells increased significantly. The most cell survival reduction (11.6 times) was revealed in the Grid bystander cells of radioresistant cell line (HN5). No statistically significant difference between 10 Gy uniform beam and Grid non-uniform beam was observed. CONCLUSIONS Various endpoints confirmed an augmented response of cells in the valley dose region of the Grid block significantly (compared with the cells irradiated by identical dose of uniform beam), suggesting the role of high-dose bystander effect which was more pronounced in resistant carcinoma cell lines. These findings could provide a partial explanation for the Grid beneficial response seen in a number of pre-clinical and clinical studies.
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Affiliation(s)
- Fatemeh Pakniyat
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Ali Nedaie
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Radiation Oncology Research Center, Cancer institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Aziz Mahmoudzadeh
- Department of Bioscience and Biotechnology, Malek-Ashtar University of Technology, Tehran, Iran
| | - Mahdieh Salimi
- Department of Medical genetics, Medical Biotechnology Institute, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Somayeh Gholami
- Radiation Oncology Research Center, Cancer institute, Tehran University of Medical Sciences, Tehran, Iran
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He G, Tang A, Xie M, Xia W, Zhao P, Wei J, Lai Y, Tang X, Zou YM, Liu H. Blood Gene Expression Profile Study Revealed the Activation of Apoptosis and p53 Signaling Pathway May Be the Potential Molecular Mechanisms of Ionizing Radiation Damage and Radiation-Induced Bystander Effects. Dose Response 2020; 18:1559325820914184. [PMID: 32284698 PMCID: PMC7119240 DOI: 10.1177/1559325820914184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/04/2020] [Accepted: 02/18/2020] [Indexed: 11/16/2022] Open
Abstract
Radiotherapy is an effective treatment for local solid tumors, but the mechanism of damage to human body caused by radiation therapy needs further study. In this study, gene expression profiles of human peripheral blood samples exposed to different doses and rates of ionizing radiation (IR) were used for bioinformatics analysis to investigate the mechanism of IR damage and radiation-induced bystander effect (RIBE). Differentially expressed genes analysis, weighted gene correlation network analysis, functional enrichment analysis, hypergeometric test, gene set enrichment analysis, and gene set variation analysis were applied to analyze the data. Moreover, receiver operating characteristic curve analysis was performed to identify core genes of IR damage. Weighted gene correlation network analysis identified 3 modules associated with IR damage, 2 were positively correlated and 1 was negatively correlated. The analysis showed that the positively correlated modules were significantly involved in apoptosis and p53 signaling pathway, and ESR1, ATM, and MYC were potential transcription factors regulating these modules. Thus, the study suggested that apoptosis and p53 signaling pathway may be the potential molecular mechanisms of IR damage and RIBE, which could be driven by ESR1, ATM, and MYC.
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Affiliation(s)
- Guangyao He
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Anzhou Tang
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Mao Xie
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Wei Xia
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Pengcheng Zhao
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jianglian Wei
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Yongjing Lai
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xianglong Tang
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Yi Ming Zou
- Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Heng Liu
- School of Information and Management, Guangxi Medical University, Nanning, Guangxi, China
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Yakovlev VA. Role of nitric oxide in the radiation-induced bystander effect. Redox Biol 2015; 6:396-400. [PMID: 26355395 PMCID: PMC4572387 DOI: 10.1016/j.redox.2015.08.018] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/27/2015] [Accepted: 08/31/2015] [Indexed: 11/27/2022] Open
Abstract
Cells that are not irradiated but are affected by “stress signal factors” released from irradiated cells are called bystander cells. These cells, as well as directly irradiated ones, express DNA damage-related proteins and display excess DNA damage, chromosome aberrations, mutations, and malignant transformation. This phenomenon has been studied widely in the past 20 years, since its first description by Nagasawa and Little in 1992, and is known as the radiation-induced bystander effect (RIBE). Several factors have been identified as playing a role in the bystander response. This review will focus on one of them, nitric oxide (NO), and its role in the stimulation and propagation of RIBE. The hydrophobic properties of NO, which permit its diffusion through the cytoplasm and plasma membranes, allow this signaling molecule to easily spread from irradiated cells to bystander cells without the involvement of gap junction intercellular communication. NO produced in irradiated tissues mediates cellular regulation through posttranslational modification of a number of regulatory proteins. The best studied of these modifications are S-nitrosylation (reversible oxidation of cysteine) and tyrosine nitration. These modifications can up- or down-regulate the functions of many proteins modulating different NO-dependent effects. These NO-dependent effects include the stimulation of genomic instability (GI) and the accumulation of DNA errors in bystander cells without direct DNA damage. Ionizing radiation stimulates generation of nitric oxide (NO). NO stimulates genomic instability by inhibiting BRCA1 protein expression. NO can diffuse and stimulate genomic instability in the bystander cells. Propagation of NO from cell-to-cell creates a “mutator fields”. Definition of the “mutator filed” is proposed.
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Affiliation(s)
- Vasily A Yakovlev
- Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, VA, USA.
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5
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Advantages and limitations of commonly used methods to assay the molecular permeability of gap junctional intercellular communication. Biotechniques 2008; 45:33-52, 56-62. [PMID: 18611167 DOI: 10.2144/000112810] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The role of gap junctional intercellular communication (GJIC) in regulation of normal growth and differentiation is becoming increasingly recognized as a major cellular function. GJIC consists of intercellular exchange of low molecular weight molecules, and is the only means for direct contact between cytoplasms of adjacent animal cells. Disturbances of GJIC have been associated with many pathological conditions, such as carcinogenesis or hereditary illness. Reliable and accurate methods for the determination of GJIC are therefore important in cell biology studies. There are several methods used successfully in numerous laboratories to measure GJIC both in vitro and in vivo. This review comments on techniques currently used to study cell-to-cell communication, either by measuring dye transfer, as in methods like microinjection, scrape loading, gap-fluorescence recovery after photobleaching (gap-FRAP), the preloading assay, and local activation of a molecular fluorescent probe (LAMP), or by measuring electrical conductance and metabolic cooperation. As we will discuss in this review, these techniques are not equivalent but instead provide complementary information. We will focus on their main advantages and limitations. Although biological applications guide the choice of techniques we describe, we also review points that must be taken into consideration before using a methodology, such as the number of cells to analyze.
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Gopinath P, Ghosh SS. Apoptotic induction with bifunctional E.coli cytosine deaminase-uracil phosphoribosyltransferase mediated suicide gene therapy is synergized by curcumin treatment in vitro. Mol Biotechnol 2007; 39:39-48. [PMID: 18092145 DOI: 10.1007/s12033-007-9026-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 11/26/2007] [Indexed: 11/26/2022]
Abstract
Development of novel suicide gene therapy vector with potential application in cancer treatment has a great impact on human health. Investigation to understand molecular mechanism of cell death is necessary to evaluate the therapeutic application of suicide vectors. For example, the bifunctional E.coli cytosine deaminase & uracil phosphoribosyltransferase fusion (CD-UPRT) gene expression is known to sensitize a wide range of cells toward nontoxic prodrug 5-flurocytosine (5-FC) by converting it to toxic compounds, but the exact pathway of cell death is yet to be defined. Herein, we investigated the mechanism of cell death by 5-FC/CD-UPRT suicide system in both cancer and non-cancer cells and found that the optimum 5-FC concentration led to programmed cell death in vitro. The CD-UPRT expression of transfected cells was measured by the RT-PCR analysis. Biochemical assays, such as mitochondrial activity (MTS) and lactate dehydrogenase (LDH) measurements exhibited cell death. Microscopic experiments showed characteristic onset of apoptosis which was further supported by internucleosomal DNA cleavage of BrdU labeled cellular DNA, appearance of characteristic laddering of chromosomal DNA and involvement of caspase pathway. Furthermore, the 5-FC/CD-UPRT-mediated apoptosis was potentiated with addition of a known anticancer agent curcumin. Our in vitro studies confirmed synergistic induction of apoptotic pathway in the combination treatment. Therefore, combination of 5-FC/CD-UPRT with curcumin could be a potential chemosensitization strategy for cancer treatment.
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Affiliation(s)
- P Gopinath
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, 781039, India
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Banaz-Yaşar F, Lennartz K, Winterhager E, Gellhaus A. Radiation-induced bystander effects in malignant trophoblast cells are independent from gap junctional communication. J Cell Biochem 2007; 103:149-61. [PMID: 17516549 DOI: 10.1002/jcb.21395] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
It is controversially discussed that irradiation induces bystander effects via gap junction channels and/or diffusible cellular factors such as nitric oxide or cytokines excreted from the cells into the environment. But up to now the molecular mechanism leading to a bystander response is not well understood. To discriminate between both mechanisms of bystander response, (i) mediated by gap junctional communication and/or (ii) mediated by diffusible molecules, we used non-communicating Jeg3 malignant trophoblast cells transfected with inducible gap junction proteins, connexin43 and connexin26, respectively, based on the Tet-On system. We co-cultivated X-ray irradiated and non-irradiated bystander Jeg3 cells for 4 h, separated both cell populations by flow cytometry and evaluated the expression of activated p53 by Western blot analysis. The experimental design was proven with communicating versus non-communicating Jeg3 cells. Interestingly, our results revealed a bystander effect which was independent from gap junctional communication properties and the connexin isoform expressed. Therefore, it seems more likely that the bystander effect is not mediated via gap junction channels but rather by paracrine mechanisms via excreted molecules in Jeg3 cells.
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Affiliation(s)
- Ferya Banaz-Yaşar
- Institute of Anatomy, University Hospital Essen, Hufelandstr. 55, 45122 Essen, Germany
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8
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Gentry BG, Boucher PD, Shewach DS. Hydroxyurea induces bystander cytotoxicity in cocultures of herpes simplex virus thymidine kinase-expressing and nonexpressing HeLa cells incubated with ganciclovir. Cancer Res 2006; 66:3845-51. [PMID: 16585212 DOI: 10.1158/0008-5472.can-05-3660] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Suicide gene therapy with the herpes simplex virus thymidine kinase (HSV-TK) cDNA and ganciclovir can elicit cytotoxicity to transgene-expressing and nonexpressing bystander cells via transfer of ganciclovir phosphates through gap junctions. HeLa cells do not exhibit bystander cytotoxicity, although we showed recently that they transfer low levels of ganciclovir phosphates to bystander cells. Here, we attempted to induce bystander cytotoxicity using hydroxyurea, an inhibitor of ribonucleotide reductase, to decrease the endogenous dGTP pool, which should lessen competition with ganciclovir triphosphate for DNA incorporation. Addition of hydroxyurea to cocultures of HSV-TK-expressing and bystander cells synergistically increased ganciclovir-mediated cytotoxicity to both cell populations while producing primarily an additive effect in cultures of 100% HSV-TK-expressing cells. Whereas HSV-TK-expressing cells in coculture were approximately 50-fold less sensitive to ganciclovir compared with cultures of 100% HSV-TK-expressing cells, addition of hydroxyurea restored ganciclovir sensitivity. Quantification of deoxynucleoside triphosphate pools showed that hydroxyurea decreased dGTP pools without significantly affecting ganciclovir triphosphate levels. Although hydroxyurea significantly increased the ganciclovir triphosphate:dGTP value for 12 to 24 hours in HSV-TK-expressing and bystander cells from coculture (1.4- to 4.9-fold), this value was increased for <12 hours (2.5-fold) in 100% HSV-TK-expressing cells. These data suggest that the prolonged increase in the ganciclovir triphosphate:dGTP value in cells in coculture resulted in synergistic cytotoxicity. Compared with enhancement of bystander cytotoxicity through modulation of gap junction intercellular communication, this strategy is superior because it increased cytotoxicity to both HSV-TK-expressing and bystander cells in coculture. This approach may improve clinical efficacy.
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Affiliation(s)
- Brian G Gentry
- Department of Pharmacology, University of Michigan Medical Center, 4713 Upjohn Center, 1310 East Catherine, Ann Arbor, MI 48109, USA
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Niculescu-Duvaz I, Springer CJ. Introduction to the background, principles, and state of the art in suicide gene therapy. Mol Biotechnol 2006; 30:71-88. [PMID: 15805578 DOI: 10.1385/mb:30:1:071] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gene therapy is defined as a technology that aims to modify the genetic component of cells to gain therapeutic benefits. Suicide gene therapy (or gene-directed enzyme prodrug therapy [GDEPT]) is a two-step treatment for cancer (especially, solid tumors). In the first step, a gene for a foreign enzyme is delivered to the tumor by a vector. Following the expression of the foreign enzyme, a prodrug is administered during the second step, which is selectively activated in the tumor. This article discusses the principles and the theorectical background of GDEPT. A special emphasis is put on enzyme/prodrug systems developed for GDEPT, the design of prodrugs and the kinetic of their activation, the types and the mechanisms of bystander effect and its immunological implications. The possible strategies to improve GDEPT are also discussed.
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Affiliation(s)
- Ion Niculescu-Duvaz
- Cancer Research, UK Centre for Cancer Therapeutics, Institute of Cancer Research, 15 Cotswold Road, Sutton, Surrey, SM2 5NG, UK
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Gentry BG, Im M, Boucher PD, Ruch RJ, Shewach DS. GCV phosphates are transferred between HeLa cells despite lack of bystander cytotoxicity. Gene Ther 2005; 12:1033-41. [PMID: 15789060 DOI: 10.1038/sj.gt.3302487] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The role of gap junctional intercellular communication (GJIC) in bystander killing with herpes simplex virus thymidine kinase (HSV-TK) and ganciclovir (GCV) was evaluated in U251 cells expressing a dominant-negative connexin 43 cDNA (DN14), and in HeLa cells, reportedly devoid of connexin protein. These cell lines both exhibited 0% GJIC when assayed by Lucifer Yellow fluorescent dye microinjection. Bystander cytotoxicity was still apparent in 50:50 cocultures of DN14 and HSV-TK-expressing U251 cells, but not in 50:50 cocultures of HeLa cells. However, the sensitivity of HeLa HSV-TK-expressing cells to GCV decreased nearly 100-fold (IC90=109 microM) when cocultured with bystander cells compared to results in 100% cultures of HSV-TK-expressing cells (IC90=1.2 microM). A more sensitive flow cytometry technique to measure GJIC over 24 h revealed that the DN14 and HeLa cells exhibited detectable levels of communication (29 and 23%, respectively). Transfer of phosphorylated GCV to HeLa bystander cells occurred within 4 h after drug addition, and GCV triphosphate (GCVTP) accumulated to 213+/-84 pmol/10(6) cells after 24 h. In addition, GCVTP levels were decreased in HSV-TK-expressing cells in coculture (867+/-33 pmol/10(6) cells) compared to 100% cultures of HSV-TK-expressing cells (1773+/-188 pmol/10(6) cells). The half-life of GCVTP in the HSV-TK-expressing cells was approximately four times that measured in the bystander cells (12.3 and 3.1 h, respectively). These data suggest that the lack of bystander cytotoxicity in HeLa cocultures is due to low transfer of phosphorylated GCV and a rapid half-life of GCVTP in the bystander cells. Thus, GCV phosphate transfer to non-HSV-TK-expressing bystander cells may mediate either bystander cell killing or sparing of HSV-TK-positive cells, depending upon the cell specific drug metabolism.
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Affiliation(s)
- B G Gentry
- Department of Pharmacology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0504, USA
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Zhang L, Sharma S, Hershman JM, Brent GA, Dubinett SM, Huang M. Iodide sensitizes genetically modified non-small cell lung cancer cells to ionizing radiation. Cancer Gene Ther 2005; 13:74-81. [PMID: 16052231 DOI: 10.1038/sj.cgt.7700875] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
While external ionizing radiation has been used for treating non-small cell lung cancer (NSCLC), improved efficacy of this modality would be an important advance. Ectopic expression of the sodium iodide symporter (NIS) and thyroperoxidase (TPO) genes in NSCLC cells facilitated concentration of iodide in NSCLC cells, which markedly induced apoptosis in vitro and in vivo. Pre-incubation of the NIS/TPO-modified NSCLC cells in iodide followed by ionizing radiation generates bystander tumoricidal effects and potently enhances tumor cell killing. This iodide-induced bystander effect is associated with enhanced gap junction intercellular communication (GJIC) activity and increased connexin-43 (Cx43) expression. Thus, iodide may serve as an enhancer to markedly improve the efficacy of radiation therapy in combined therapeutic modalities.
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Affiliation(s)
- L Zhang
- Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine at UCLA and Veterans Affairs Greater Los Angeles Healthcare System, CA 90095, USA
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Perry MJ, Todryk SM, Dalgleish AG. The role of herpes simplex virus thymidine kinase in the treatment of solid tumours. Expert Opin Investig Drugs 2005; 8:777-85. [PMID: 15992130 DOI: 10.1517/13543784.8.6.777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Suicide gene therapy is the approach whereby the genetic alteration of a cell renders it susceptible to an otherwise non-toxic prodrug. Suicide gene therapy for solid tumours has progressed rapidly since the concept was originally described: nearly all tumour types have been explored, with some, such as glioma, melanoma and colon cancer frequently used experimentally. The exciting aspect of suicide gene therapy is the bystander effect, the phenomenon whereby there is extended tumour death when only a small fraction is transfected with the suicide gene. This phenomenon implies that there is a reduced need to target specifically all tumour cells, as the effect mechanism itself carries out this function. The bystander effect mode of action has not yet been fully characterised, but the role of gap junctions and the immune system are implicated as the main instruments in its potentiation. This approach is also amenable to pharmacological intervention, which may help to optimise parameters prior to commencing suicide gene therapy. Clinical trails have already commenced using this form of treatment and results are eagerly awaited.
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Affiliation(s)
- M J Perry
- Department of Urology, St George's Hospital Medical School, Cranmer Terrace, London SW17 0QT, UK.
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Wu DH, Liu L, Chen LH. Antitumor effects and radiosensitization of cytosine deaminase and thymidine kinase fusion suicide gene on colorectal carcinoma cells. World J Gastroenterol 2005; 11:3051-5. [PMID: 15918188 PMCID: PMC4305838 DOI: 10.3748/wjg.v11.i20.3051] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 07/24/2004] [Accepted: 08/23/2004] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS Colorectal carcinoma cell line SW480 was transfected with adenovirus expression vector containing cytosine deaminase (CD) and thymidine kinase (TK) fusion gene. The expression of CD-TK fusion gene was detected by reverse transcriptase-polymerase chain reaction. The toxic effect of ganciclovir (GCV) and 5-fluorocytosine (5-FC) on infected cells was determined by MTT assay. The radiosensitization of double suicide gene was evaluated by clonogenic assay. RESULTS After prodrugs were used, the survival rate of colorectal carcinoma cells was markedly decreased. When GCV and 5-FC were used in combination, the cytotoxicity and bystander effect were markedly superior to a single prodrug (chi2 = 30.371, P<0.01). Both GCV and 5-FC could sensitize colorectal carcinoma cells to the toxic effect of radiation, and greater radiosensitization was achieved when both prodrug were used in combination. CONCLUSION CD-TK double suicide gene can kill and radiosensitize colorectal carcinoma cells.
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Affiliation(s)
- De-Hua Wu
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong Province, China.
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Jiang JX, Gu S. Gap junction- and hemichannel-independent actions of connexins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2004; 1711:208-14. [PMID: 15955305 PMCID: PMC1831832 DOI: 10.1016/j.bbamem.2004.10.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 10/06/2004] [Accepted: 10/07/2004] [Indexed: 01/22/2023]
Abstract
Connexins have been known to be the protein building blocks of gap junctions and mediate cell-cell communication. In contrast to the conventional dogma, recent evidence suggests that in addition to forming gap junction channels, connexins possess gap junction-independent functions. One important gap junction-independent function for connexins is to serve as the major functional component for hemichannels, the un-apposed halves of gap junctions. Hemichannels, as independent functional units, play roles that are different from that of gap junctions in the cell. The other functions of connexins appear to be gap junction- and hemichannel-independent. Published studies implicate the latter functions of connexins in cell growth, differentiation, tumorigenicity, injury, and apoptosis, although the mechanistic aspects of these actions remain largely unknown. In this review, gap junction- and hemichannel-independent functions of connexins are summarized, and the molecular mechanisms underlying these connexin functions are speculated and discussed.
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Affiliation(s)
- Jean X Jiang
- Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
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Gadi VK, Alexander SD, Waud WR, Allan PW, Parker WB, Sorscher EJ. A long-acting suicide gene toxin, 6-methylpurine, inhibits slow growing tumors after a single administration. J Pharmacol Exp Ther 2003; 304:1280-4. [PMID: 12604707 DOI: 10.1124/jpet.102.044743] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have demonstrated antitumor activity against refractory human glioma and pancreatic tumors with 6-methylpurine (MeP) using either a suicide gene therapy strategy to selectively release 6-methylpurine in tumor cells or direct intratumoral injection of 6-methylpurine itself. A single i.p. injection in mice of the prodrug 9-beta-D-[2-deoxyribofuranosyl]-6-methylpurine (MeP-dR; 134 mg/kg) caused sustained regression lasting over 70 days of D54 (human glioma) tumors transduced with the Escherichia coli purine nucleoside phosphorylase (PNP), and a single intratumoral injection of 6-methylpurine (5-10 mg/kg) elicited prolonged delays of the growth of D54 tumors and CFPAC human pancreatic carcinoma. Because the D54 tumor doubling time is >15 days, the experiments indicate that prodrug activation by E. coli PNP engenders destruction of both dividing and nondividing tumor compartments in vivo and, therefore, address a fundamental barrier that has limited the development of suicide gene strategies in the past. A prolonged retention time of 6-methylpurine metabolites in tumors was noted in vivo (T(1/2) >24 h compared with a serum half-life of <1 h). By high-pressure liquid chromatography, metabolites of [(3)H]MeP-dR were 5- to 6-fold higher in tumors expressing E. coli PNP. These experiments point to new endpoints for monitoring E. coli PNP suicide gene therapy, including intratumoral enzymatic activity, in situ (intratumoral) prodrug conversion, and tumor regressions after direct injection of a suicide gene toxin. The findings also help explain the strong in vivo bystander killing mechanism ascribed by several laboratories to E. coli PNP in the past.
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Affiliation(s)
- Vijayakrishna K Gadi
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Rousselle C, Barbier M, Comte VV, Alcouffe C, Clement-Lacroix J, Chancel G, Ronot X. Innocuousness and intracellular distribution of PKH67: a fluorescent probe for cell proliferation assessment. In Vitro Cell Dev Biol Anim 2001; 37:646-55. [PMID: 11776970 DOI: 10.1290/1071-2690(2001)037<0646:iaidop>2.0.co;2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PKH dyes were initially developed by Horan et al. to provide appropriate probes for in vitro and in vivo cell tracking. It has been reported for many cell types that PKH bind irreversibly to the cell membrane without significantly affecting cell growth. Thus, these probes provide an opportunity for long-term cell monitoring and the identification of cells of interest among a heterogeneous cell population. An important feature is that upon cell division, the probe is partitioned equally between each daughter cell, making it possible to quantify tell fluorescence by flow cytometry. In this situation. the flow cytometric study of PKH67 characteristics shows that this probe does not affect the main cell-functions such as viability or proliferation. Moreover, the intracellular distribution of PKH67 is demonstrated by following its kinetics of internalization by confocal microscopy. These results present PKH67 as a probe suitable for dynamic analysis of cell proliferation as well as the study of intracellular localization and membrane recycling mechanisms.
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Affiliation(s)
- C Rousselle
- Laboratoire de Dynamique Cellulaire, Ecole Pratique des Hautes Etudes, Université Joseph Fourier, La Tronche, France
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Drake RR, Pitlyk K, McMasters RA, Mercer KE, Young H, Moyer MP. Connexin-independent ganciclovir-mediated killing conferred on bystander effect-resistant cell lines by a herpes simplex virus-thymidine kinase-expressing colon cell line. Mol Ther 2000; 2:515-23. [PMID: 11082325 DOI: 10.1006/mthe.2000.0192] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A novel gap junction-independent mechanism for ganciclovir-mediated bystander effect killing by a herpes simplex virus thymidine kinase (HSV-TK)-expressing SW620 human colon tumor cell line has been characterized. The mechanism of the HSV-TK/GCV bystander effect for many tumor cell lines has been demonstrated to be due to connexin gap junction transfer of phosphorylated ganciclovir (GCV) metabolites; however, there may be as yet uncharacterized connexin-independent mechanisms for the effect. To address this, the bystander effect was further evaluated in a panel of cell lines mixed with homologous HSV-TK-expressing cell lines, a SW620.TK cell line, or a high connexin43-expressing PA-317.TK cell line. Of the 10 cell lines tested, 4 were found to be resistant to bystander effect killing by their homologous HSV-TK-expressing cell lines and the PA-317.TK cells, but all of the cell lines were sensitive to GCV killing when mixed with the SW620.TK cells. The SW620.TK cells were then further evaluated for any indication of extracellular GCV metabolite efflux. Culture medium from SW620.TK cells labeled with [(3)H]GCV was evaluated for the presence of GCV nucleotides by ion-exchange column separation and HPLC analysis. The presence of GCV mono-, di-, and triphosphate metabolites in the medium was detected. Inclusion in the medium of inhibitors of extracellular phosphatases and ecto-ATPases increased the proportion of GCV metabolites recovered. These results indicate that phosphorylated GCV metabolites can be effluxed from SW620.TK cells and that some type of cellular uptake mechanism independent of gap junctions exists for nucleotide entry into neighboring cells.
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Affiliation(s)
- R R Drake
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
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Gadi VK, Alexander SD, Kudlow JE, Allan P, Parker WB, Sorscher EJ. In vivo sensitization of ovarian tumors to chemotherapy by expression of E. coli purine nucleoside phosphorylase in a small fraction of cells. Gene Ther 2000; 7:1738-43. [PMID: 11083495 DOI: 10.1038/sj.gt.3301286] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This report examines a major barrier to suicide gene therapy in cancer and other diseases: namely, bystander cell killing. Existing vectors for in vivo gene delivery are inefficient and often transduce or transfect less than 1% of target cells. The E. coli PNP gene brings about cellular necrosis under conditions when 1 in 100 to 1 in 1000 cells express the gene product in vitro. In vivo bystander killing at or near this magnitude has not been reported previously. In the present experiments, transfection of cells with the E. coli PNP gene controlled by a SV40 promoter resulted in 30 nmol 6-methyl purine deoxyriboside (MeP-dR) converted per milligram tumor cell extract per hour (or conversion units (CU)). This level of expression led to elimination of entire populations of tumor cells in vitro after treatment with MeP-dR. Much earlier killing was observed using a tat transactivated E. coli PNP vector (approximately seven-fold higher activity, 230 CU). In vivo effects on tumor growth were next examined. Human ovarian tumors transfected with E. coli PNP were excised 5 days after i.p. implantation from the peritoneal cavities of mice in order to determine both E. coli PNP enzymatic activity and the fraction of cells expressing the gene. PNP activity at 5 days after gene transfer was approximately 170 CU and was expressed in approximately 0.1% of the tumor cells as judged by in situ hybridization. The expression of E. coli PNP at this level produced a 30% increase in life span (P < 0.001) and 49% reduction in tumor size (P < 0.005) after MeP-dR treatment, as compared with control tumors. Our observations lead to the conclusion that pronounced bystander killing by E. coli PNP is conferred in vivo, and that vectors capable of transgene expression in as few as one in 1000 cells can produce substantial antitumor effects if expression on a per cell basis is very high.
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Affiliation(s)
- V K Gadi
- Department of Physiology, University of Alabama at Birmingham, 35294-0005, USA
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Springer CJ, Niculescu-Duvaz I. Prodrug-activating systems in suicide gene therapy. J Clin Invest 2000; 105:1161-7. [PMID: 10791987 PMCID: PMC315452 DOI: 10.1172/jci10001] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- C J Springer
- Cancer Research Campaign Centre for Cancer Therapeutics at the Institute of Cancer Research, Sutton, Surrey, United Kingdom.
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Inase N, Horita K, Tanaka M, Miyake S, Ichioka M, Yoshizawa Y. Use of gastrin-releasing peptide promoter for specific expression of thymidine kinase gene in small-cell lung carcinoma cells. Int J Cancer 2000; 85:716-9. [PMID: 10699954 DOI: 10.1002/(sici)1097-0215(20000301)85:5<716::aid-ijc19>3.0.co;2-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For specific transduction of herpes simplex virus thymidine kinase (HSV-tk) into human small-cell lung carcinoma (SCLC) cells, we explored the 5'-flanking region (-1.1 kb) of the gastrin-releasing peptide (GRP) gene as a lung cancer-specific promoter. RT-PCR analysis demonstrated expression of GRP mRNA in the SBC5 human SCLC cell line but not in the RERF human SCLC cell line, the A549 human lung adenocarcinoma cell line or the HeLa human uterine cervix epithelioid carcinoma cell line. A reporting vector containing the GRP promoter (pGL2-GRP) exhibited higher luciferase activity in SBC5 than in the other 3 cell lines. After transfecting an expression vector containing the GRP promoter-bound HSV-tk gene (pGRP-TK) into the cells, we measured their sensitivity to ganciclovir (GCV). In SBC5, pGRP-tk-transfected cells became about 100 times more sensitive to GCV than parental cells in vitro. In nude mice, tumors of pGRP-tk-transfected SBC5 regressed completely after i.p. administration of GCV. GRP promoter might be a good tool for tumor-specific transduction of suicide genes in GRP-expressing SCLC cells.
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Affiliation(s)
- N Inase
- The Pulmonary Medicine, Tokyo Medical and Dental University, Tokyo, Japan
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Bai S, Du L, Liu W, Whittle IR, He L. Tentative novel mechanism of the bystander effect in glioma gene therapy with HSV-TK/GCV system. Biochem Biophys Res Commun 1999; 259:455-9. [PMID: 10362529 DOI: 10.1006/bbrc.1999.0766] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although many works support gap junctional intercellular communication (GJIC) having a close relation to bystander cell killing in herpes simplex virus thymidine kinase (HSV-TK) gene and ganciclovir (GCV) treatment, our previous work suggested that other factors involved in bystander effect besides GJIC exist. To confirm our primary work, we evaluated the mode of the bystander cell (C6) co-cultured with TK-positive cells (TF10.2) in our designed "insert plates" in which two cell lines could be separated but share the same medium. Another method that we used was adding the supernatant from the medium of GCV-treated TF10.2 cells to the wild type C6. Growth inhibition of the bystander cells was observed despite the absence of GJIC. In addition, apoptotic cell death of TK+ cells and bystander cells was obvious. These studies suggested that other pathways besides cell-cell contacts may play a role in bystander cell killing; the factors released from TK-positive cells could induce apoptosis of bystander cells.
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Affiliation(s)
- S Bai
- Shanghai Research Center of Life Sciences, Chinese Academy of Sciences, Shanghai, People's Republic of China
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