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Leggett SE, Brennan MC, Martinez S, Tien J, Nelson CM. Relatively Rare Populations of Invasive Cells Drive Progression of Heterogeneous Tumors. Cell Mol Bioeng 2024; 17:7-24. [PMID: 38435793 PMCID: PMC10902221 DOI: 10.1007/s12195-023-00792-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/19/2023] [Indexed: 03/05/2024] Open
Abstract
Introduction Breast tumors often display an astonishing degree of spatial and temporal heterogeneity, which are associated with cancer progression, drug resistance, and relapse. Triple-negative breast cancer (TNBC) is a particularly aggressive and heterogeneous subtype for which targeted therapies are scarce. Consequently, patients with TNBC have a poorer overall prognosis compared to other breast cancer patients. Within heterogeneous tumors, individual clonal subpopulations may exhibit differences in their rates of growth and degrees of invasiveness. We hypothesized that such phenotypic heterogeneity at the single-cell level may accelerate tumor progression by enhancing the overall growth and invasion of the entire tumor. Methods To test this hypothesis, we isolated and characterized clonal subpopulations with distinct morphologies and biomarker expression from the inherently heterogeneous 4T1 mouse mammary carcinoma cell line. We then leveraged a 3D microfluidic tumor model to reverse-engineer intratumoral heterogeneity and thus investigate how interactions between phenotypically distinct subpopulations affect tumor growth and invasion. Results We found that the growth and invasion of multiclonal tumors were largely dictated by the presence of cells with epithelial and mesenchymal traits, respectively. The latter accelerated overall tumor invasion, even when these cells comprised less than 1% of the initial population. Consistently, tumor progression was delayed by selectively targeting the mesenchymal subpopulation. Discussion This work reveals that highly invasive cells can dominate tumor phenotype and that specifically targeting these cells can slow the progression of heterogeneous tumors, which may help inform therapeutic approaches. Supplementary Information The online version contains supplementary material available at 10.1007/s12195-023-00792-w.
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Affiliation(s)
- Susan E. Leggett
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, 25 William Street, Princeton, NJ 08544 USA
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801 USA
| | - Molly C. Brennan
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, 25 William Street, Princeton, NJ 08544 USA
| | - Sophia Martinez
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, 25 William Street, Princeton, NJ 08544 USA
| | - Joe Tien
- Department of Biomedical Engineering, Boston University, Boston, MA 02215 USA
| | - Celeste M. Nelson
- Department of Chemical & Biological Engineering, Princeton University, 303 Hoyt Laboratory, 25 William Street, Princeton, NJ 08544 USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA
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Mark JKK, Lim CSY, Nordin F, Tye GJ. Expression of mammalian proteins for diagnostics and therapeutics: a review. Mol Biol Rep 2022; 49:10593-10608. [PMID: 35674877 PMCID: PMC9175168 DOI: 10.1007/s11033-022-07651-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/25/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Antibodies have proven to be remarkably successful for biomedical applications. They play important roles in epidemiology and medicine from diagnostics of diseases to therapeutics, treating diseases from incessant chronic diseases such as rheumatology to pandemic outbreaks. With no end in sight for the demand for antibody products, optimizations and new techniques must be expanded to accommodate this. METHODS AND RESULTS This review discusses optimizations and techniques for antibody production through choice of discovery platforms, expression systems, cell culture mediums, and other strategies to increase expression yield. Each system has its own merits and demerits, and the strategy chosen is critical in addressing various biological aspects. CONCLUSIONS There is still insufficient evidence to validate the efficacy of some of these techniques, and further research is needed to consolidate these industrial production systems. There is no doubt that more strategies, systems, and pipelines will contribute to enhance biopharmaceutical production.
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Affiliation(s)
- Jacqueline Kar Kei Mark
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Penang, Minden, Malaysia
| | - Crystale Siew Ying Lim
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, No 1 Jalan Menara Gading, UCSI Heights, Taman Connaught, 56000, Kuala Lumpur, Cheras, Malaysia
| | - Fazlina Nordin
- Tissue Engineering Centre (TEC), Universiti Kebangsaan Malaysia Medical Centre (UKMMC), 56000, Kuala Lumpur, Cheras, Malaysia
| | - Gee Jun Tye
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Penang, Minden, Malaysia.
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Nanometer-Resolution Imaging of Living Cells Using Soft X-ray Contact Microscopy. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12147030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Soft X-ray microscopy is a powerful technique for imaging cells with nanometer resolution in their native state without chemical fixation, staining, or sectioning. The studies performed in several laboratories have demonstrated the potential of applying this technique for imaging the internal structures of intact cells. However, it is currently used mainly on synchrotrons with restricted access. Moreover, the operation of these instruments and the associated sample-preparation protocols require interdisciplinary and highly specialized personnel, limiting their wide application in practice. This is why soft X-ray microscopy is not commonly used in biological laboratories as an imaging tool. Thus, a laboratory-based and user-friendly soft X-ray contact microscope would facilitate the work of biologists. A compact, desk-top laboratory setup for soft X-ray contact microscopy (SXCM) based on a laser-plasma soft X-ray source, which can be used in any biological laboratory, together with several applications for biological imaging, are described. Moreover, the perspectives of the correlation of SXCM with other super-resolution imaging techniques based on the current literature are discussed.
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Horikawa M, Sabe H, Onodera Y. Strategies for all-at-once and stepwise selection of cells with multiple genetic manipulations. Biochem Biophys Res Commun 2021; 582:93-99. [PMID: 34695756 DOI: 10.1016/j.bbrc.2021.10.016] [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: 09/09/2021] [Revised: 10/01/2021] [Accepted: 10/06/2021] [Indexed: 11/23/2022]
Abstract
The genetic manipulation of cells followed by their selection is indispensable for cell biological research. Although antibiotics-resistant genes are commonly used as selection markers, optimization of the condition for each selective agent is required. Here we utilized split-inteins and the drug-selectable marker puromycin N-acetyltransferase (PAC) to develop a system that enables the selection of cells simultaneously or sequentially transfected with multiple genetic constructs, using only puromycin. The active PAC enzyme was reconstituted by intein-mediated trans-splicing at several inherent or engineered serine/cysteine residues. Multiple splitting and reconstitution of active PAC was readily achieved by selecting optimum division sites based on the cellular tolerance to various puromycin concentrations. To achieve the stepwise selection method, PAC-intein fragments were transduced into cells using a virus-like particle (VLP) composed of HIV-1 gag-pol and VSV-G. The PAC-intein-VLP successfully conferred sufficient PAC activity for puromycin selection, which was quickly diminished in the absence of the VLP. Our findings demonstrate a versatile strategy for establishing markers for all-at-once or stepwise selection of multiple genetic manipulations, which will be useful in many fields of biology.
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Affiliation(s)
- Mei Horikawa
- Department of Molecular Biology, Faculty of Mecidine and Graduate School of Medicine, Hokkaido University, Sapporo, 060-8638, Japan
| | - Hisataka Sabe
- Department of Molecular Biology, Faculty of Mecidine and Graduate School of Medicine, Hokkaido University, Sapporo, 060-8638, Japan
| | - Yasuhito Onodera
- Department of Molecular Biology, Faculty of Mecidine and Graduate School of Medicine, Hokkaido University, Sapporo, 060-8638, Japan; Global Center for Biomedical Science and Engineering, Faculty of Medicine, Hokkaido University, Sapporo, 060-8638, Japan.
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Matinyan N, Karkhanis MS, Gonzalez Y, Jain A, Saltzman A, Malovannaya A, Sarrion-Perdigones A, Dierick HA, Venken KJT. Multiplexed drug-based selection and counterselection genetic manipulations in Drosophila. Cell Rep 2021; 36:109700. [PMID: 34525356 PMCID: PMC8480232 DOI: 10.1016/j.celrep.2021.109700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 06/10/2021] [Accepted: 08/20/2021] [Indexed: 01/27/2023] Open
Abstract
The power of Drosophila melanogaster as a model system relies on tractable germline genetic manipulations. Despite Drosophila's expansive genetics toolbox, such manipulations are still accomplished one change at a time and depend predominantly on phenotypic screening. We describe a drug-based genetic platform consisting of four selection and two counterselection markers, eliminating the need to screen for modified progeny. These markers work reliably individually or in combination to produce specific genetic outcomes. We demonstrate three example applications of multiplexed drug-based genetics by generating (1) transgenic animals, expressing both components of binary overexpression systems in a single transgenesis step; (2) dual selectable and counterselectable balancer chromosomes; and (3) selectable, fluorescently tagged P[acman] bacterial artificial chromosome (BAC) strains. We perform immunoprecipitation followed by proteomic analysis on one tagged BAC line, demonstrating our platform's applicability to biological discovery. Lastly, we provide a plasmid library resource to facilitate custom transgene design and technology transfer to other model systems.
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Affiliation(s)
- Nick Matinyan
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Integrative Molecular Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mansi S Karkhanis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yezabel Gonzalez
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Antrix Jain
- Advanced Technology Cores, Mass Spectrometry Proteomics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alexander Saltzman
- Advanced Technology Cores, Mass Spectrometry Proteomics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Anna Malovannaya
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Advanced Technology Cores, Mass Spectrometry Proteomics, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alejandro Sarrion-Perdigones
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Herman A Dierick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Koen J T Venken
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Integrative Molecular Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX 77030, USA; McNair Medical Institute at The Robert and Janice McNair Foundation, Baylor College of Medicine, Houston, TX 77030, USA.
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Guo C, Fordjour FK, Tsai SJ, Morrell JC, Gould SJ. Choice of selectable marker affects recombinant protein expression in cells and exosomes. J Biol Chem 2021; 297:100838. [PMID: 34051235 PMCID: PMC8258971 DOI: 10.1016/j.jbc.2021.100838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/14/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022] Open
Abstract
Transgenic mammalian cells are used for numerous research, pharmaceutical, industrial, and clinical purposes, and dominant selectable markers are often used to enable the selection of transgenic cell lines. Using HEK293 cells, we show here that the choice of selectable marker gene has a significant impact on both the level of recombinant protein expression and the cell-to-cell variability in recombinant protein expression. Specifically, we observed that cell lines generated with the NeoR or BsdR selectable markers and selected in the antibiotics G418 or blasticidin, respectively, displayed the lowest level of recombinant protein expression as well as the greatest cell-to-cell variability in transgene expression. In contrast, cell lines generated with the BleoR marker and selected in zeocin yielded cell lines that expressed the highest levels of linked recombinant protein, approximately 10-fold higher than those selected using the NeoR or BsdR markers, as well as the lowest cell-to-cell variability in recombinant protein expression. Intermediate yet still-high levels of expression were observed in cells generated with the PuroR- or HygR-based vectors and that were selected in puromycin or hygromycin, respectively. Similar results were observed in the African green monkey cell line COS7. These data indicate that each combination of selectable marker and antibiotic establishes a threshold below which no cell can survive and that these thresholds vary significantly between different selectable markers. Moreover, we show that choice of selectable marker also affects recombinant protein expression in cell-derived exosomes, consistent with the hypothesis that exosome protein budding is a stochastic rather than determinative process.
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Affiliation(s)
- Chenxu Guo
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Francis K Fordjour
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Shang Jui Tsai
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - James C Morrell
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA
| | - Stephen J Gould
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA.
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Abstract
Natural or synthetic genetic modules can lose their function over long-term evolution if the function is costly. How populations can evolve to restore such broken function is poorly understood. To test the reversibility of evolutionary breakdown, we use yeast cell populations with a chromosomally integrated synthetic gene circuit. In previous evolution experiments the gene circuit lost its costly function through various mutations. By exposing such mutant populations to conditions where regaining gene circuit function would be beneficial, we find adaptation scenarios with or without repairing lost gene circuit function. These results are important for drug resistance or future synthetic biology applications where evolutionary loss and regain of function play a significant role. Evolutionary reversibility—the ability to regain a lost function—is an important problem both in evolutionary and synthetic biology, where repairing natural or synthetic systems broken by evolutionary processes may be valuable. Here, we use a synthetic positive-feedback (PF) gene circuit integrated into haploid Saccharomyces cerevisiae cells to test if the population can restore lost PF function. In previous evolution experiments, mutations in a gene eliminated the fitness costs of PF activation. Since PF activation also provides drug resistance, exposing such compromised or broken mutants to both drug and inducer should create selection pressure to regain drug resistance and possibly PF function. Indeed, evolving 7 PF mutant strains in the presence of drug revealed 3 adaptation scenarios through genomic, PF-external mutations that elevate PF basal expression, possibly by affecting transcription, translation, degradation, and other fundamental cellular processes. Nonfunctional mutants gained drug resistance without ever developing high expression, while quasifunctional and dysfunctional PF mutants developed high expression nongenetically, which then diminished, although more slowly for dysfunctional mutants where revertant clones arose. These results highlight how intracellular context, such as the growth rate, can affect regulatory network dynamics and evolutionary dynamics, which has important consequences for understanding the evolution of drug resistance and developing future synthetic biology applications.
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8
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Kugler A, Zorin B, Didi-Cohen S, Sibiryak M, Gorelova O, Ismagulova T, Kokabi K, Kumari P, Lukyanov A, Boussiba S, Solovchenko A, Khozin-Goldberg I. Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses. PLANT & CELL PHYSIOLOGY 2019; 60:1205-1223. [PMID: 30668793 DOI: 10.1093/pcp/pcz013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/15/2019] [Indexed: 05/16/2023]
Abstract
Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L. incisa, to produce knockdown lines for the Δ5 desaturase gene. Two lines, termed modified lines, which were isolated during screening for transgenic events, demonstrated alterations in their LC-PUFA profile, ARA-biosynthesis gene expression and lipid class distribution. In line M5-78, which appeared to carry a mutation in the Δ6 elongase gene, LC-PUFA were substituted by 18:3n-6 in all glycerolipids. Line M2-35, for which the exact genetic background has not been established, displayed a dramatic reduction in 20:4n-6, concomitant with an augmented proportion of 18:1n-9, in particular in the extraplastidial membrane lipids and TAG. The physiological responses of the modified lines to stressful conditions were compared with the wild type and the Δ5 desaturase mutant. In the N-replete cells of modified lines, the frequency of lipid droplets was reduced, while a number of starch grains increased, suggesting altered partitioning of assimilated carbon into reserve products. Furthermore, both lines exhibited reduced ability to accumulate TAG under N deprivation and recover from N starvation. Both lines demonstrated lower photosynthetic pigment contents, impairments in photosynthesis under a range of stressful conditions, and less efficient functioning of photoprotection under optimal conditions. Possible implications of fatty acids modifications in the stress response of L. incisa are addressed.
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Affiliation(s)
- Amit Kugler
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Boris Zorin
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Shoshana Didi-Cohen
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Maria Sibiryak
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Olga Gorelova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Tatiana Ismagulova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Kamilya Kokabi
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Puja Kumari
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexander Lukyanov
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexei Solovchenko
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
- Institute of Agriculture and Technology, Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
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Buck JM, Río Bártulos C, Gruber A, Kroth PG. Blasticidin-S deaminase, a new selection marker for genetic transformation of the diatom Phaeodactylum tricornutum. PeerJ 2018; 6:e5884. [PMID: 30488015 PMCID: PMC6250098 DOI: 10.7717/peerj.5884] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/08/2018] [Indexed: 01/25/2023] Open
Abstract
Most genetic transformation protocols for the model diatom Phaeodactylum tricornutum rely on one of two available antibiotics as selection markers: Zeocin (a formulation of phleomycin D1) or nourseothricin. This limits the number of possible consecutive genetic transformations that can be performed. In order to expand the biotechnological possibilities for P. tricornutum, we searched for additional antibiotics and corresponding resistance genes that might be suitable for use with this diatom. Among the three different antibiotics tested in this study, blasticidin-S and tunicamycin turned out to be lethal to wild-type cells at low concentrations, while voriconazole had no detectable effect on P. tricornutum. Testing the respective resistance genes, we found that the blasticidin-S deaminase gene (bsr) effectively conferred resistance against blasticidin-S to P. tricornutum. Furthermore, we could show that expression of bsr did not lead to cross-resistances against Zeocin or nourseothricin, and that genetically transformed cell lines with resistance against Zeocin or nourseothricin were not resistant against blasticidin-S. In a proof of concept, we also successfully generated double resistant (against blasticidin-S and nourseothricin) P. tricornutum cell lines by co-delivering the bsr vector with a vector conferring nourseothricin resistance to wild-type cells.
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Affiliation(s)
- Jochen M Buck
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Ansgar Gruber
- Department of Biology, University of Konstanz, Konstanz, Germany.,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Peter G Kroth
- Department of Biology, University of Konstanz, Konstanz, Germany
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10
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Hunter M, Yuan P, Vavilala D, Fox M. Optimization of Protein Expression in Mammalian Cells. ACTA ACUST UNITED AC 2018; 95:e77. [DOI: 10.1002/cpps.77] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Stepanenko AA, Heng HH. Transient and stable vector transfection: Pitfalls, off-target effects, artifacts. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 773:91-103. [DOI: 10.1016/j.mrrev.2017.05.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 05/09/2017] [Accepted: 05/13/2017] [Indexed: 12/15/2022]
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12
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Lo CA, Greben AW, Chen BE. Generating stable cell lines with quantifiable protein production using CRISPR/Cas9-mediated knock-in. Biotechniques 2017; 62:165-174. [DOI: 10.2144/000114534] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 02/17/2017] [Indexed: 11/23/2022] Open
Abstract
Cell lines expressing foreign genes have been widely used to produce a variety of recombinant proteins. However, generating recombinant protein–expressing cell lines is usually a lengthy process and the resulting protein expression levels are often inconsistent. Here, we describe an efficient method for making stable cell lines expressing any recombinant protein of interest in a controllable and quantifiable manner. We integrate transgenes into specific genomic loci using CRISPR/Cas9 such that transgene expression is driven by endogenous promoters to ensure consistent and predictable expression of the recombinant protein. Expression levels can be predetermined by selecting promoters from genes with the desired level of expression. To quantify recombinant protein expression, a protein quantitation reporter (PQR) is incorporated between the endogenous and foreign genes. The PQR allows equimolar production of the endogenous protein, the recombinant protein, and a fluorescent reporter. As a result, expression levels of both the endogenous and recombinant proteins can be continuously monitored using fluorescence.
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Affiliation(s)
- Chiu-An Lo
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre
- Departments of Medicine and Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada
| | - Alexander W. Greben
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre
- Departments of Medicine and Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada
| | - Brian Edwin Chen
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre
- Departments of Medicine and Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada
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13
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Hyperforin Exhibits Antigenotoxic Activity on Human and Bacterial Cells. Molecules 2017; 22:molecules22010167. [PMID: 28117734 PMCID: PMC6155625 DOI: 10.3390/molecules22010167] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/22/2016] [Accepted: 01/12/2017] [Indexed: 11/17/2022] Open
Abstract
Hyperforin (HF), a substance that accumulates in the leaves and flowers of Hypericum perforatum L. (St. John’s wort), consists of a phloroglucinol skeleton with lipophilic isoprene chains. HF exhibits several medicinal properties and is mainly used as an antidepressant. So far, the antigenotoxicity of HF has not been investigated at the level of primary genetic damage, gene mutations, and chromosome aberrations, simultaneously. The present work is designed to investigate the potential antigenotoxic effects of HF using three different experimental test systems. The antigenotoxic effect of HF leading to the decrease of primary/transient promutagenic genetic changes was detected by the alkaline comet assay on human lymphocytes. The HF antimutagenic effect leading to the reduction of gene mutations was assessed using the Ames test on the standard Salmonella typhimurium (TA97, TA98, and TA100) bacterial strains, and the anticlastogenic effect of HF leading to the reduction of chromosome aberrations was evaluated by the in vitro mammalian chromosome aberration test on the human tumor cell line HepG2 and the non-carcinogenic cell line VH10. Our findings provided evidence that HF showed antigenotoxic effects towards oxidative mutagen zeocin in the comet assay and diagnostic mutagen (4-nitroquinoline-1-oxide) in the Ames test. Moreover, HF exhibited an anticlastogenic effect towards benzo(a)pyrene and cisplatin in the chromosome aberration test.
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14
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Johnson CH, Fisher TS, Hoang LT, Felding BH, Siuzdak G, O’Brien PJ. Luciferase does not Alter Metabolism in Cancer Cells. Metabolomics 2014; 10:354-360. [PMID: 24791164 PMCID: PMC4002053 DOI: 10.1007/s11306-014-0622-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Luciferase transfected cell lines are used extensively for cancer models, revealing valuable biological information about disease mechanisms. However, these genetically encoded reporters, while useful for monitoring tumor response in cancer models, can impact cell metabolism. Indeed firefly luciferase and fatty acyl-CoA synthetases differ by a single amino acid, raising the possibility that luciferase activity might alter metabolism and introduce experimental artifacts. Therefore knowledge of the metabolic response to luciferase transfection is of significant importance, especially given the thousands of research studies using luciferase as an in vivo bioluminescence imaging (BLI) reporter. Untargeted metabolomics experiments were performed to examine three different types of lymphoblastic leukemia cell lines (Ramos, Raji and SUP T1) commonly used in cancer research, each were analyzed with and without vector transduction. The Raji model was also tested under perturbed starvation conditions to examine potential luciferase-mediated stress responses. The results showed that no significant metabolic differences were observed between parental and luciferase transduced cells for each cell line, and that luciferase overexpression does not alter cell metabolism under basal or perturbed conditions.
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Affiliation(s)
- Caroline H. Johnson
- Scripps Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA, USA
| | - Timothy S. Fisher
- Pfizer Worldwide Research and Development, La Jolla Laboratories 10724 Science Center Drive, San Diego, CA, USA
| | - Linh T. Hoang
- Scripps Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA, USA
| | - Brunhilde H. Felding
- Departments of Molecular and Experimental Medicine and Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Gary Siuzdak
- Scripps Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA, USA
- Correspondence to: and
| | - Peter J. O’Brien
- Pfizer Worldwide Research and Development, La Jolla Laboratories 10724 Science Center Drive, San Diego, CA, USA
- Correspondence to: and
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15
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Hasegawa J, Higaki T, Hamamura Y, Kurihara D, Kutsuna N, Higashiyama T, Hasezawa S, Matsunaga S. Increase in Invaginated Vacuolar Membrane Structure Caused by Plant Cell Expansion by Genotoxic Stress Induced by DNA Double-Strand Breaks. CYTOLOGIA 2014. [DOI: 10.1508/cytologia.79.467] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Junko Hasegawa
- Department of Applied Biological Science, Faculty of Science and Technology Tokyo University of Science
| | - Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
| | - Yuki Hamamura
- JST, ERATO, Higashiyama Live-Holonics Project, Nagoya University
| | - Daisuke Kurihara
- JST, ERATO, Higashiyama Live-Holonics Project, Nagoya University
- Division of Biological Sciences, Graduate School of Science, Nagoya University
| | - Natsumaro Kutsuna
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
| | - Tetsuya Higashiyama
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University
- JST, ERATO, Higashiyama Live-Holonics Project, Nagoya University
- Division of Biological Sciences, Graduate School of Science, Nagoya University
| | - Seiichiro Hasezawa
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
| | - Sachihiro Matsunaga
- Department of Applied Biological Science, Faculty of Science and Technology Tokyo University of Science
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16
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Aw R, Polizzi KM. Can too many copies spoil the broth? Microb Cell Fact 2013; 12:128. [PMID: 24354594 PMCID: PMC3878197 DOI: 10.1186/1475-2859-12-128] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 12/16/2013] [Indexed: 02/02/2023] Open
Abstract
The success of Pichia pastoris as a heterologous expression system lies predominantly in the impressive yields that can be achieved due to high volumetric productivity. However, low specific productivity still inhibits the potential success of this platform. Multi-(gene) copy clones are potentially a quick and convenient method to increase recombinant protein titer, yet they are not without their pitfalls. It has been more than twenty years since the first reported use of multi-copy clones and it is still an active area of research to find the fastest and most efficient method for generating these strains. It has also become apparent that there is not always a linear correlation between copy number and protein titer, leading to in-depth investigations into how to minimize the negative impact of secretory stress and achieve clonal stability.
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Affiliation(s)
- Rochelle Aw
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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17
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Lanza AM, Kim DS, Alper HS. Evaluating the influence of selection markers on obtaining selected pools and stable cell lines in human cells. Biotechnol J 2013; 8:811-21. [PMID: 23450727 DOI: 10.1002/biot.201200364] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 01/29/2013] [Accepted: 02/28/2013] [Indexed: 12/14/2022]
Abstract
Selection markers are common genetic elements used in recombinant cell line development. While several selection systems exist for use in mammalian cell lines, no previous study has comprehensively evaluated their performance in the isolation of recombinant populations and cell lines. Here we examine four antibiotics, hygromycin B, neomycin, puromycin, and Zeocin™, and their corresponding selector genes, using a green fluorescent protein (GFP) as a reporter in two model cell lines, HT1080 and HEK293. We identify Zeocin™ as the best selection agent for cell line development in human cells. In comparison to the other selection systems, Zeocin™ is able to identify populations with higher fluorescence levels, which in turn leads to the isolation of better clonal populations and less false positives. Furthermore, Zeocin™-resistant populations exhibit better transgene stability in the absence of selection pressure compared to other selection agents. All isolated Zeocin™-resistant clones, regardless of cell type, exhibited GFP expression. By comparison, only 79% of hygromycin B-resistant, 47% of neomycin-resistant, and 14% of puromycin-resistant clones expressed GFP. Based on these results, we rank Zeocin™ > hygromycin B ∼ puromycin > neomycin for cell line development in human cells. Furthermore, this study demonstrates that selection marker choice does indeed impact cell line development.
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Affiliation(s)
- Amanda M Lanza
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas, USA
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18
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Spadafora ND, Doonan JH, Herbert RJ, Bitonti MB, Wallace E, Rogers HJ, Francis D. Arabidopsis T-DNA insertional lines for CDC25 are hypersensitive to hydroxyurea but not to zeocin or salt stress. ANNALS OF BOTANY 2011; 107:1183-92. [PMID: 20647223 PMCID: PMC3091795 DOI: 10.1093/aob/mcq142] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 05/21/2023]
Abstract
BACKGROUND AND AIMS In yeasts and animals, cyclin-dependent kinases are key regulators of cell cycle progression and are negatively and positively regulated by WEE1 kinase and CDC25 phosphatase, respectively. In higher plants a full-length orthologue of CDC25 has not been isolated but a shorter gene with homology only to the C-terminal catalytic domain is present. The Arabidopis thaliana;CDC25 can act as a phosphatase in vitro. Since in arabidopsis, WEE1 plays an important role in the DNA damage/DNA replication checkpoints, the role of Arath;CDC25 in conditions that induce these checkpoints or induce abiotic stress was tested. Methods arath;cdc25 T-DNA insertion lines, Arath;CDC25 over-expressing lines and wild type were challenged with hydroxyurea (HU) and zeocin, substances that stall DNA replication and damage DNA, respectively, together with an abiotic stressor, NaCl. A molecular and phenotypic assessment was made of all genotypes Key RESULTS There was a null phenotypic response to perturbation of Arath;CDC25 expression under control conditions. However, compared with wild type, the arath;cdc25 T-DNA insertion lines were hypersensitive to HU, whereas the Arath;CDC25 over-expressing lines were relatively insensitive. In particular, the over-expressing lines consistently outgrew the T-DNA insertion lines and wild type when challenged with HU. All genotypes were equally sensitive to zeocin and NaCl. CONCLUSIONS Arath;CDC25 plays a role in overcoming stress imposed by HU, an agent know to induce the DNA replication checkpoint in arabidopsis. However, it could not enhance tolerance to either a zeocin treatment, known to induce DNA damage, or salinity stress.
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Affiliation(s)
- Natasha D. Spadafora
- School of Biosciences, Cardiff University, Main College, Cardiff CF10 3AT, UK
- Institute of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, UK
| | - John H. Doonan
- Department of Cell Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | - Robert J. Herbert
- Institute of Science and the Environment, University of Worcester, Henwick Grove, Worcester WR2 6AJ, UK
| | - M. Beatrice Bitonti
- Dipartimento di Ecologia, Università della Calabria, Arcavacata di Rende, I-87030 Cosenza, Italy
| | - Emily Wallace
- School of Biosciences, Cardiff University, Main College, Cardiff CF10 3AT, UK
| | - Hilary J. Rogers
- School of Biosciences, Cardiff University, Main College, Cardiff CF10 3AT, UK
| | - Dennis Francis
- School of Biosciences, Cardiff University, Main College, Cardiff CF10 3AT, UK
- For correspondence. E-mail
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19
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Delacôte F, Deriano L, Lambert S, Bertrand P, Saintigny Y, Lopez BS. Chronic exposure to sublethal doses of radiation mimetic Zeocin selects for clones deficient in homologous recombination. Mutat Res 2006; 615:125-33. [PMID: 17174359 DOI: 10.1016/j.mrfmmm.2006.11.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 10/30/2006] [Accepted: 11/17/2006] [Indexed: 01/27/2023]
Abstract
DNA double-strand breaks (DSBs) are highly toxic lesions leading to genome variability/instability. The balance between homologous recombination (HR) and non-homologous end-joining (NHEJ), two alternative DSB repair systems, is essential to ensure genome maintenance in mammalian cells. Here, we transfected CHO hamster cells with the pcDNA3.1/Zeo plasmid, and selected transfectants with Zeocin, a bleomycin analog which produces DSBs. Despite the presence of a Zeocin resistance gene in pcDNA3.1/Zeo, Zeocin induced 8-10 gamma-H2AX foci per cell. This shows that the Zeocin resistance gene failed to fully detoxify cells treated with Zeocin, and that during selection cells were submitted to a chronic sublethal DSB stress. Selected clones show decreases in both spontaneous and induced intrachromosomal HR. In contrast, in an in vitro assay, these clones show an increase in NHEJ products specific to the KU86 pathway. We selected cells, in the absence of pcDNA3.1/Zeo, with low and sublethal doses of Zeocin, producing a mean 8-10 gamma-H2AX foci per cell. Newly selected clones exhibited similar phenotypes: HR decrease accompanied by an increase in KU86-dependent NHEJ efficiency. Thus chronic exposure to sublethal numbers of DSBs selects cells whose HR versus NHEJ balance is altered. This may well have implications for radio- and chemotherapy, and for management of environmental hazards.
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Affiliation(s)
- Fabien Delacôte
- UMR CNRS/CEA 217, DSV, DRR, CEA, 18 route du panorama, 92265 Fontenay aux Roses, Cédex, France
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