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Chen L, Hong W, Ren W, Xu T, Qian Z, He Z. Recent progress in targeted delivery vectors based on biomimetic nanoparticles. Signal Transduct Target Ther 2021; 6:225. [PMID: 34099630 PMCID: PMC8182741 DOI: 10.1038/s41392-021-00631-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 02/05/2023] Open
Abstract
Over the past decades, great interest has been given to biomimetic nanoparticles (BNPs) since the rise of targeted drug delivery systems and biomimetic nanotechnology. Biological vectors including cell membranes, extracellular vesicles (EVs), and viruses are considered promising candidates for targeted delivery owing to their biocompatibility and biodegradability. BNPs, the integration of biological vectors and functional agents, are anticipated to load cargos or camouflage synthetic nanoparticles to achieve targeted delivery. Despite their excellent intrinsic properties, natural vectors are deliberately modified to endow multiple functions such as good permeability, improved loading capability, and high specificity. Through structural modification and transformation of the vectors, they are pervasively utilized as more effective vehicles that can deliver contrast agents, chemotherapy drugs, nucleic acids, and genes to target sites for refractory disease therapy. This review summarizes recent advances in targeted delivery vectors based on cell membranes, EVs, and viruses, highlighting the potential applications of BNPs in the fields of biomedical imaging and therapy industry, as well as discussing the possibility of clinical translation and exploitation trend of these BNPs.
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Affiliation(s)
- Li Chen
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Weiqi Hong
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wenyan Ren
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ting Xu
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Zhiyong Qian
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhiyao He
- Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China.
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Lufino MMP, Edser PAH, Wade-Martins R. Advances in high-capacity extrachromosomal vector technology: episomal maintenance, vector delivery, and transgene expression. Mol Ther 2008; 16:1525-38. [PMID: 18628754 DOI: 10.1038/mt.2008.156] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Recent developments in extrachromosomal vector technology have offered new ways of designing safer, physiologically regulated vectors for gene therapy. Extrachromosomal, or episomal, persistence in the nucleus of transduced cells offers a safer alternative to integrating vectors which have become the subject of safety concerns following serious adverse events in recent clinical trials. Extrachromosomal vectors do not cause physical disruption in the host genome, making these vectors safe and suitable tools for several gene therapy targets, including stem cells. Moreover, the high insert capacity of extrachromosomal vectors allows expression of a therapeutic transgene from the context of its genomic DNA sequence, providing an elegant way to express normal splice variants and achieve physiologically regulated levels of expression. Here, we describe past and recent advances in the development of several different extrachromosomal systems, discuss their retention mechanisms, and evaluate their use as expression vectors to deliver and express genomic DNA loci. We also discuss a variety of delivery systems, viral and nonviral, which have been used to deliver episomal vectors to target cells in vitro and in vivo. Finally, we explore the potential for the delivery and expression of extrachromosomal transgenes in stem cells. The long-term persistence of extrachromosomal vectors combined with the potential for stem cell proliferation and differentiation into a wide range of cell types offers an exciting prospect for therapeutic interventions.
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Affiliation(s)
- Michele M P Lufino
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Mathis JM, Williams BJ, Sibley DA, Carroll JL, Li J, Odaka Y, Barlow S, Nathan CAO, Li BDL, DeBenedetti A. Cancer-specific targeting of an adenovirus-delivered herpes simplex virus thymidine kinase suicide gene using translational control. J Gene Med 2006; 8:1105-20. [PMID: 16802401 DOI: 10.1002/jgm.935] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two technical hurdles, gene delivery and target specificity, have hindered the development of effective cancer gene therapies. In order to circumvent the problem of tumor specificity, the suicide gene, HSV-1 thymidine kinase (HSV-Tk), was modified with a complex 5' upstream-untranslated region (5'-UTR) that limits efficient translation to cells expressing high levels of the translation initiation factor, eIF4E. Since previous studies have shown that most tumor cells express elevated levels of eIF4E, tumor-specific gene delivery was optimized by incorporation of the 5'-UTR-modified suicide gene (HSV-UTk) into an adenovirus vector (Ad-CMV-UTk). The efficacy of this novel approach of targeting suicide gene expression and limiting cytotoxicity by means of translational restriction was tested in vitro with the use of the human breast cancer cell lines (MCF-7, MDA-MB435, and ZR-75-1). As controls, normal MCF10A, HMEC, and HMSC cell lines that express relatively low levels of eIF4E were used. Real-time reverse-transcription polymerase chain reaction (RT-PCR) was used to quantify HSV-Tk mRNA for cells infected with Ad-CMV-UTk as well as with Ad-CMV-Tk (a control adenovirus in which HSV-Tk is not regulated at the level of translation). Translation of HSV-Tk in the Ad-infected cells was measured by Western blot analysis. In addition, cytotoxicity was determined following treatment with the pro-drug ganciclovir (GCV) using an MTT viability assay. Finally, microPET imaging was used to assess cancer cell-specific expression of HSV-Tk and expression in normal tissues in vivo after intraperitoneal injection of Ad-CMV-Tk or Ad-CMV-UTk. These data collectively showed enhanced cancer cell-specific gene expression and reduced normal tissue gene expression for the Ad-HSV-UTk compared to the Ad-CMV-Tk, leading to increased cancer cell-enhanced GCV cytotoxicity. These results indicate that translational targeting of suicide gene expression in tumor cells in vitro and in vivo is effective and may provide a platform for enhanced cancer gene therapy specificity.
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Affiliation(s)
- J Michael Mathis
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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Sen SP, De Benedetti A. TLK1B promotes repair of UV-damaged DNA through chromatin remodeling by Asf1. BMC Mol Biol 2006; 7:37. [PMID: 17054786 PMCID: PMC1626478 DOI: 10.1186/1471-2199-7-37] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Accepted: 10/20/2006] [Indexed: 11/21/2022] Open
Abstract
Background The mammalian protein kinase TLK1 is a homologue of Tousled, a gene involved in flower development in Arabidopsis thaliana. The function of TLK1 is not well known, although knockout of the gene in Drosophila, or expression of a dominant negative mutant in mouse mammary cells causes loss of nuclear divisions and chromosome mis-segregation. TLK1B is a splice variant of TLK1 and it confers radioresistance in a normal mammary mouse cell line possibly due to increased chromatin remodeling capacity, but the mechanism of resistance remains to be fully elucidated. Results We now show that TLK1B also affords protection against UV radiation. We find that nuclear extracts isolated from TLK1B-containing mouse cells promote more efficient chromatin assembly than comparable extracts lacking TLK1B. TLK1B-containing extracts are also more efficient in repair of UV-damaged plasmid DNA assembled into nucleosomes. One of the two known substrates of TLK1 (or TLK1B) is the histone chaperone Asf1, and immuno-inactivation experiments suggest that TLK1B increases UV-repair through the action of Asf1 on chromatin assembly/disassembly. Conclusion Our studies provide evidence for TLK1B-mediated phosphorylation of Asf1 triggering DNA repair. We suggest that this occurs via Asf1-mediated chromatin assembly at the sites of UV damage.
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Affiliation(s)
- Siddhartha P Sen
- Department of Biochemistry and Molecular Biology and the Feist Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
| | - Arrigo De Benedetti
- Department of Biochemistry and Molecular Biology and the Feist Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
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Sunavala-Dossabhoy G, Balakrishnan SK, Sen S, Nuthalapaty S, De Benedetti A. The radioresistance kinase TLK1B protects the cells by promoting repair of double strand breaks. BMC Mol Biol 2005; 6:19. [PMID: 16156902 PMCID: PMC1242231 DOI: 10.1186/1471-2199-6-19] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 09/12/2005] [Indexed: 11/10/2022] Open
Abstract
Background The mammalian protein kinase TLK1 is a homologue of Tousled, a gene involved in flower development in Arabidopsis thaliana. The function of TLK1 is not well known, although knockout of the gene in Drosophila or expression of a dominant negative mutant in mouse cells causes loss of nuclear divisions and missegregation of chromosomes probably, due to alterations in chromatin remodeling capacity. Overexpression of TLK1B, a spliced variant of the TLK1 mRNA, in a model mouse cell line increases it's resistance to ionizing radiation (IR) or the radiomimetic drug doxorubicin, also likely due to changes in chromatin remodeling. TLK1B is translationally regulated by the availability of the translation factor eIF4E, and its synthesis is activated by IR. The reason for this mechanism of regulation is likely to provide a rapid means of promoting repair of DSBs. TLK1B specifically phosphorylates histone H3 and Asf1, likely resulting in changes in chromatin structure, particularly at double strand breaks (DSB) sites. Results In this work, we provide several lines of evidence that TLK1B protects the cells from IR by facilitating the repair of DSBs. First, the pattern of phosphorylation and dephosphorylation of H2AX and H3 indicated that cells overexpressing TLK1B return to pre-IR steady state much more rapidly than controls. Second, the repair of episomes damaged with DSBs was much more rapid in cells overexpressing TLK1B. This was also true for repair of genomic damage. Lastly, we demonstrate with an in vitro repair system that the addition of recombinant TLK1B promotes repair of a linearized plasmid incubated with nuclear extract. In addition, TLK1B in this in vitro system promotes the assembly of chromatin as shown by the formation of more highly supercoiled topomers of the plasmid. Conclusion In this work, we provide evidence that TLK1B promotes the repair of DSBs, likely as a consequence of a change in chromatin remodeling capacity that must precede the assembly of repair complexes at the sites of damage.
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Affiliation(s)
- Gulshan Sunavala-Dossabhoy
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center. 1501 Kings Highway, Shreveport, LA 71130-3932, USA
| | - Sri Kripa Balakrishnan
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center. 1501 Kings Highway, Shreveport, LA 71130-3932, USA
| | - Siddhartha Sen
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center. 1501 Kings Highway, Shreveport, LA 71130-3932, USA
| | - Sam Nuthalapaty
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center. 1501 Kings Highway, Shreveport, LA 71130-3932, USA
| | - Arrigo De Benedetti
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center. 1501 Kings Highway, Shreveport, LA 71130-3932, USA
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Van Craenenbroeck K, Vanhoenacker P, Roman I, Haegeman G. Orientation-dependent gene expression with Epstein-Barr virus-derived vectors. FEBS Lett 2003; 555:489-94. [PMID: 14675761 DOI: 10.1016/s0014-5793(03)01311-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Episomal vectors, described for efficient and regulated expression of heterologous proteins in mammalian cells, have the advantage that they persist in multiple copies in the cell without integrating into the chromosome. To efficiently express heterologous proteins we used such a vector based on elements of the Epstein-Barr virus (EBV), namely the sequences coding for Epstein-Barr nuclear antigen 1 and the viral origin of replication. Because constitutive expression is often deleterious to the cell, we combined the interferon-inducible Mx promoter with this EBV-derived vector. This resulted in an efficient and strictly regulated expression of the reporter gene chloramphenicol acetyltransferase (CAT) and of the neurotransmitter receptor h5-HT(1B), reaching levels of 16 ng CAT/mg cytoplasmic protein and 1300 fmol receptor/mg membrane protein, respectively. For both proteins, the expression levels were influenced by the orientation of the expression cassette. The higher expression in the favored orientation did not result from a higher copy number of these episomes. Northern analysis revealed a transcriptional read-through from the thymidine kinase promoter on the episomal vector, which interfered with the transcription of the heterologous gene in the less favored orientation.
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DeFatta RJ, Li Y, De Benedetti A. Selective killing of cancer cells based on translational control of a suicide gene. Cancer Gene Ther 2002; 9:573-8. [PMID: 12082457 DOI: 10.1038/sj.cgt.7700468] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2002] [Indexed: 01/25/2023]
Abstract
The translation initiation factor, eIF4E, is commonly overexpressed in solid tumors. This elevation allows for efficient translation of mRNA that are normally repressed by their 5' untranslated region, many of which encode growth-promoting proteins. This property was exploited to modulate the synthesis of HTK at the translational level to selectively kill cancer cells. Various breast cancer cell lines can efficiently synthesize HTK from the translationally regulated mRNA, whereas normal cells cannot. Accordingly, only cancer cells were killed at low concentrations of ganciclovir. By altering the expression of eIF4E, it was possible to modulate the sensitivity of various cell lines to ganciclovir.
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Affiliation(s)
- Robert J DeFatta
- Department of Biochemistry and Molecular Biology and the Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA
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Chow CM, Athanassiadou A, Raguz S, Psiouri L, Harland L, Malik M, Aitken MA, Grosveld F, Antoniou M. LCR-mediated, long-term tissue-specific gene expression within replicating episomal plasmid and cosmid vectors. Gene Ther 2002; 9:327-36. [PMID: 11938452 DOI: 10.1038/sj.gt.3301654] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2001] [Accepted: 12/18/2001] [Indexed: 11/08/2022]
Abstract
Locus control regions (LCRs) are transcriptional regulatory elements, which possess a dominant chromatin remodelling and transcriptional activating capability conferring full physiological levels of expression on a gene linked in cis, when integrated into the host cell genome. Using the human beta-globin LCR (betaLCR) as a model, we show that this class of control element can drive high levels of tissue-specific gene expression in stably transfected cultured cells from within an Epstein-Barr virus-based plasmid REV. Furthermore, a 38-kb betaLCR minilocus-REV cosmid vector was efficiently retained and maintained therapeutic levels of beta-globin transgene expression in the absence of drug selective pressure over a 2-month period of continuous culture equivalent to at least 60 generations. This demonstrates for the first time the feasibility of using REVs for gene therapy of the haemoglobinopathies. Importantly, our results demonstrate that as in the case of integrated transgenes, expression from within REVs is prone to silencing but that the inclusion of the betaLCR prevented this repression of gene function. Therefore, appropriate control elements to provide and maintain tissue-specific gene expression, as well as the episomal status of REVs is a crucial feature in vector design. Our data suggest that LCRs can contribute to this vital function.
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Affiliation(s)
- C-M Chow
- Nuclear Biology Group, Division of Medical and Molecular Genetics, GKT School of Medicine, Guy's Hospital, London, UK
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Anthony C, Zong Q, De Benedetti A. Overexpression of eIF4E in Saccharomyces cerevisiae causes slow growth and decreased alpha-factor response through alterations in CLN3 expression. J Biol Chem 2001; 276:39645-52. [PMID: 11479284 DOI: 10.1074/jbc.m101564200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The association of G(1) cyclins and Cdc28/cyclin-dependent protein kinase catalyzes the cell cycle entry (Start) in budding yeast. Activation of Start is presumed to be triggered by a post-transcriptional increase in Cln3 during early G(1). Cells arrested by mating pheromone show a loss of cyclin-dependent protein kinase activity caused by transcriptional shutoff of cyclins and/or inhibition by Far1. We report that overexpression of eIF4E (Cdc33), a rate-limiting translation initiation factor, causes an increase in CLN3 mRNA translation, which results in increased expression of CLN2 and in slow growth and decreased alpha-factor response. This phenotype was abrogated in a Deltacln3 or Deltacln2 background. We isolated the transcription factor MBP1 as a multicopy suppressor of the growth and alpha-factor response defects. Furthermore, elevated MBP1, a transcriptional regulator of cyclins, altered the transcriptional start site in CLN3 mRNA, shifting it 45 nucleotides upstream of the normal. This lengthened 5'-untranslated region likely reduces translation efficiency and down-regulates CLN3 protein synthesis, thereby correcting for the excess translation promoted by elevated Cdc33. In addition, the CLN2 mRNA level returned to normal. We propose that regulation of translation initiation by Cdc33 plays a pivotal role in the activation of Start and cell cycle progression in budding yeast.
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Affiliation(s)
- C Anthony
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
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Li Y, DeFatta R, Anthony C, Sunavala G, De Benedetti A. A translationally regulated Tousled kinase phosphorylates histone H3 and confers radioresistance when overexpressed. Oncogene 2001; 20:726-38. [PMID: 11314006 DOI: 10.1038/sj.onc.1204147] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2000] [Revised: 11/30/2000] [Accepted: 12/05/2000] [Indexed: 11/09/2022]
Abstract
The gene Tousled of Arabidopsis Thaliana encodes a protein kinase which, when mutated, results in abnormal flower development. From a library of mRNAs that are translationally upregulated by overexpression of the translation initiation factor 4E, we identified a mammalian Tousled Like kinase (TLK1B). The human TLK1B mRNA contains a 5'UTR 1088-nt-long with two upstream AUG codons, and was found to be very inhibitory for translation. The TLK1B protein localizes almost exclusively to the nuclei. TLK1B overexpression in mammalian cells rendered them more resistant to ionizing radiation (IR). Purified TLK1B phosphorylated histone H3 at S(10) with high specificity both in a mix of core histones and in isolated chromatin, suggesting that histone H3 is a physiological substrate for TLK1B. Moreover, overexpression of TLK1B in transfected cells resulted in a higher degree of H3 phosphorylation. Expression of TLK1B in a yeast strain that harbors a temperature-sensitive mutation of the major H3 kinase, Ipl1, complemented the growth defect; restored normal levels of histone H3 phosphorylation; and increased their resistance to IR. Phosphorylation of H3 has been linked to the activation of the immediate-early genes upon mitogenic stimulation, and to chromatin condensation during mitotic/meiotic events. A possible role for TLK1B in radioprotection is discussed.
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Affiliation(s)
- Y Li
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
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Van Craenenbroeck K, Vanhoenacker P, Haegeman G. Episomal vectors for gene expression in mammalian cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5665-78. [PMID: 10971576 DOI: 10.1046/j.1432-1327.2000.01645.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An important reason for preferring mammalian cells for heterologous gene expression is their ability to make authentic proteins containing post-translational modifications similar to those of the native protein. The development of expression systems for mammalian cells has been ongoing for several years, resulting in a wide variety of effective expression vectors. The aim of this review is to highlight episomal expression vectors. Such episomal plasmids are usually based on sequences from DNA viruses, such as BK virus, bovine papilloma virus 1 and Epstein-Barr virus. In this review we will mainly focus on the improvements made towards the usefulness of these systems for gene expression studies and gene therapy.
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Abstract
Progress in diverse scientific fields has been realized partly by the continued refinement of mammalian gene expression vectors. A growing understanding of biological processes now allows the design of vector components to meet specific objectives. Thus, gene expression in a tissue-selective or ubiquitous manner may be accomplished by selecting appropriate promoter/enhancer elements; stabilization of labile mRNAs may be effected through removal of 3' untranslated regions or fusion to heterologous stabilizing sequences; protein targeting to selected tissues or different organelles is carried out using specific signal sequences; fusion moieties effect the detection, enhanced yield, surface expression, prolongation of half-life, and facile purification of recombinant proteins; and careful tailoring of the codon content of heterologous genes enhances protein production from poorly translated transcripts. The use of viral as well as nonviral genetic elements in vectors allows the stable replication of episomal elements without the need for chromosomal integration. The development of baculovirus vectors for both transient and stable gene expression in mammalian cells has expanded the utility of such vectors for a broad range of cell types. Internal ribosome entry sites are now widely used in many applications that require coexpression of different genes. Progress in gene targeting techniques is likely to transform gene expression and amplification in mammalian cells into a considerably less labor-intensive operation. Future progress in the elucidation of eukaryotic protein degradation pathways holds promise for developing methods to minimize proteolysis of specific recombinant proteins in mammalian cells and tissues.
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Affiliation(s)
- S C Makrides
- EIC Laboratories, Inc., Norwood, Massachusetts, 02062, USA
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Joyeux A, Balaguer P, Germain P, Boussioux AM, Pons M, Nicolas JC. Engineered cell lines as a tool for monitoring biological activity of hormone analogs. Anal Biochem 1997; 249:119-30. [PMID: 9212863 DOI: 10.1006/abio.1997.2147] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- A Joyeux
- INSERM U439, Montpellier, France
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15
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Turck J, Pollock AS, Lee LK, Marti HP, Lovett DH. Matrix metalloproteinase 2 (gelatinase A) regulates glomerular mesangial cell proliferation and differentiation. J Biol Chem 1996; 271:15074-83. [PMID: 8663054 DOI: 10.1074/jbc.271.25.15074] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A biologic role for the 72-kDa gelatinase A (matrix metalloproteinase 2; MMP-2), beyond simple extracellular matrix turnover, was evaluated in glomerular mesangial cells. To determine the significance of MMP-2 secretion for the acquisition of the inflammatory phenotype, we reduced the constitutive secretion of MMP-2 by cultured mesangial cells with antisense RNA expressed by an episomally replicating vector or with specific anti-MMP-2 ribozymes expressed by a retroviral transducing vector. The phenotype of the transfected, or retrovirally infected, cells was profoundly altered from the activated state and closely approximated that of quiescent cells in vivo. The prominent differences included a change in the synthesis and organization of the extracellular matrix, loss of activation markers, and a virtually total exit from the cell cycle. Reconstitution with exogenous active, but not latent MMP-2, induced a rapid return to the inflammatory phenotype in vitro. This effect was specific to MMP-2, because the closely related MMP-9 did not reproduce these changes. Furthermore, this pro-inflammatory effect of MMP-2 is dependent upon the active form of the enzyme, which can be produced by an autocatalytic activation process on the mesangial cell plasma membrane. It is concluded that MMP-2 acts directly upon mesangial cells to permit the development of an inflammatory phenotype. Specific inhibition of MMP-2 activity in vivo may represent an alternate means of ameliorating complex inflammatory processes by affecting the phenotype of the synthesizing cells, per se.
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Affiliation(s)
- J Turck
- Department of Medicine, San Francisco Veterans Affairs Medical Center and University of California, San Francisco, California 94121, USA
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Sabbioni S, Negrini M, Rimessi P, Manservigi R, Barbanti-Brodano G. A BK virus episomal vector for constitutive high expression of exogenous cDNAs in human cells. Arch Virol 1995; 140:335-9. [PMID: 7710358 DOI: 10.1007/bf01309866] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A BK virus (BKV) episomal vector (pRPneoCMV) was constructed for expression of cDNAs under control of the cytomegalovirus (CMV) immediate-early promoter. Transfection of pRPneoCMV for expression of the chloramphenicol acetyltransferase (CAT) gene in several human cell lines showed that the CMV promoter is more efficient than the HIV-1 and RSV LTRs in directing gene expression from episomal vectors. In 293 human cells pRPneoCMV/CAT is twenty times more active in CAT expression than the well known pSV2CAT vector in COS7 cells. Stable expression of the gene of the herpes simplex virus type 1 and type 2 glycoprotein G, cloned into pRPneoCMV, was obtained in 293 cells. This vector will allow direct cloning of newly synthesized cDNAs whose expression can be monitored in human cells.
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Affiliation(s)
- S Sabbioni
- Institute of Microbiology, School of Medicine, University of Ferrara, Italy
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Rhoads RE, Lamphear BJ. Cap-independent translation of heat shock messenger RNAs. Curr Top Microbiol Immunol 1995; 203:131-53. [PMID: 7555088 DOI: 10.1007/978-3-642-79663-0_7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- R E Rhoads
- Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130-3932, USA
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Rhoads RE, Joshi-Barve S, Rinker-Schaeffer C. Mechanism of action and regulation of protein synthesis initiation factor 4E: effects on mRNA discrimination, cellular growth rate, and oncogenesis. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1993; 46:183-219. [PMID: 8234784 DOI: 10.1016/s0079-6603(08)61022-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- R E Rhoads
- Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130
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Expression of antisense RNA against initiation factor eIF-4E mRNA in HeLa cells results in lengthened cell division times, diminished translation rates, and reduced levels of both eIF-4E and the p220 component of eIF-4F. Mol Cell Biol 1991. [PMID: 1922056 DOI: 10.1128/mcb.11.11.5435] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HeLa cells were transformed to express antisense RNA against initiation factor eIF-4E mRNA from an inducible promoter. In the absence of inducer, these cells (AS cells) were morphologically similar to control cells but grew four- to sevenfold more slowly. Induction of antisense RNA production was lethal. Both eIF-4E mRNA and protein levels were reduced in proportion to the degree of antisense RNA expression, as were the rates of protein synthesis in vivo and in vitro. Polysomes were disaggregated with a concomitant increase in ribosomal subunits. Translation in vitro was restored by addition of the initiation factor complex eIF-4F but not by eIF-4E alone. Immunological analysis revealed that the p220 component of eIF-4F was decreased in extracts of AS cells and undetectable in AS cells treated with inducer, suggesting that p220 and eIF-4E levels are coordinately regulated. eIF-4A, another component of eIF-4F, was unaltered.
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De Benedetti A, Joshi-Barve S, Rinker-Schaeffer C, Rhoads RE. Expression of antisense RNA against initiation factor eIF-4E mRNA in HeLa cells results in lengthened cell division times, diminished translation rates, and reduced levels of both eIF-4E and the p220 component of eIF-4F. Mol Cell Biol 1991; 11:5435-45. [PMID: 1922056 PMCID: PMC361686 DOI: 10.1128/mcb.11.11.5435-5445.1991] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
HeLa cells were transformed to express antisense RNA against initiation factor eIF-4E mRNA from an inducible promoter. In the absence of inducer, these cells (AS cells) were morphologically similar to control cells but grew four- to sevenfold more slowly. Induction of antisense RNA production was lethal. Both eIF-4E mRNA and protein levels were reduced in proportion to the degree of antisense RNA expression, as were the rates of protein synthesis in vivo and in vitro. Polysomes were disaggregated with a concomitant increase in ribosomal subunits. Translation in vitro was restored by addition of the initiation factor complex eIF-4F but not by eIF-4E alone. Immunological analysis revealed that the p220 component of eIF-4F was decreased in extracts of AS cells and undetectable in AS cells treated with inducer, suggesting that p220 and eIF-4E levels are coordinately regulated. eIF-4A, another component of eIF-4F, was unaltered.
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Affiliation(s)
- A De Benedetti
- Department of Biochemistry, University of Kentucky Medical Center, Lexington 40536
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