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Sample records for cho cell lines

  1. The genomic sequence of the Chinese hamster ovary (CHO)-K1 cell line

    DEFF Research Database (Denmark)

    Xu, Xun; Pan, Shengkai; Liu, Xin;

    2011-01-01

    Chinese hamster ovary (CHO)-derived cell lines are the preferred host cells for the production of therapeutic proteins. Here we present a draft genomic sequence of the CHO-K1 ancestral cell line. The assembly comprises 2.45 Gb of genomic sequence, with 24,383 predicted genes. We associate most...... of the assembled scaffolds with 21 chromosomes isolated by microfluidics to identify chromosomal locations of genes. Furthermore, we investigate genes involved in glycosylation, which affect therapeutic protein quality, and viral susceptibility genes, which are relevant to cell engineering and regulatory concerns....... Homologs of most human glycosylation-associated genes are present in the CHO-K1 genome, although 141 of these homologs are not expressed under exponential growth conditions. Many important viral entry genes are also present in the genome but not expressed, which may explain the unusual viral resistance...

  2. CHO cell line specific prediction and control of recombinant monoclonal antibody N-glycosylation.

    Science.gov (United States)

    Grainger, Rhian K; James, David C

    2013-11-01

    Here we demonstrate that it is possible to predict and control N-glycan processing of a secreted recombinant monoclonal antibody during manufacturing process development using a combination of statistical modelling and comparative measurement of cell surface glycans using fluorescent lectins. Using design of experiments--response surface modelling (DoE-RSM) methodology to adjust the relative media concentrations of known metabolic effectors of galactosylation (manganese, galactose, and uridine) we have shown that β1,4-galactosylation of the same recombinant IgG4 monoclonal antibody produced by different CHO cell lines can be precisely controlled in a cell line specific manner. For two cell lines, monoclonal antibody galactosylation could be increased by over 100% compared to control, non-supplemented cultures without a reduction in product titre and with minimal effect on cell growth. Analysis of galactosylation effector interactions by DoE-RSM indicated that Mn²⁺ alone was necessary but not sufficient to improve galactosylation, and that synergistic combinations of Gal and Urd were necessary to maximize galactosylation, whilst minimizing the deleterious effect of Urd on cell growth. To facilitate rapid cell culture process development we also tested the hypothesis that substrate-level control of cellular galactosylation would similarly affect both cell surface and secreted monoclonal antibody glycans, enabling facile indirect prediction of product glycan processing. To support this hypothesis, comparative quantitation of CHO cell surface β1,4-galactosylation by flow cytometry using fluorescent derivatives of RCA and ConA lectins revealed that substrate-controlled variation in monoclonal antibody galactosylation and cell surface galactosylation were significantly correlated. Taken together, these data show that precision control of a complex, dynamic cellular process essential for the definition of protein product molecular heterogeneity and bioactivity is

  3. HIGH DENSITY CULTIVATION OF GENETICALLY-ENGINEERED CHO CELL LINES WITH MICROCARRIER CULTURE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    肖成祖; 黄子才; 刘凤云; 郭志霞; 高丽华

    1994-01-01

    Genetically-enginecred CHO cell lines,rβ-13and CLF-8B2,were cultivated with the MC-1 microcarrier cul-ture system.The cell density could be enhanced by increasing the concentration of microcarrier.At a microcarrier concentration of 10 mg/ml.the cell density could reach 4 to 5×106 cells/ml.It was shown that these cell itnes would spontaneously release from the microcarrier to attach to and proliferate on fresh microcatriera.We were thus able to scale up cultivation using a simple methcd,i.e.by adding fresh mlcrocarriers and medium directiy in-to the culture system to about 2,4 or 8 times the original volume.Using a 2 L bioreactor for several weeks at medium perfusion rates of 0.5 to 3working volumes.Prourokinase was stably secreted.

  4. Effects of glutamine and asparagine on recombinant antibody production using CHO-GS cell lines.

    Science.gov (United States)

    Xu, Ping; Dai, Xiao-Ping; Graf, Erica; Martel, Richard; Russell, Reb

    2014-01-01

    A unique and nontraditional approach using glutamine and asparagine supplements for CHO-glutamine synthetase (GS) cell lines was studied. In our experiments, we found that a decrease in pH and an increase in cell death occurred in production phase of a GS cell line, leading to reduced antibody expression and lower antibody yields. The experimental results and the statistical analysis (ANOVA) indicated that additions of glutamine and asparagine in the basal and feed media were effective to buffer the cell culture pH, reduce lactate generation, maintain a higher cell viability profile, and improve antibody productivity. In bench-top bioreactors, glutamine and asparagine supplementation helped to prevent cell death, improve antibody yield, and reduce base usage. Glutamine is normally excluded from culture media for GS cell lines to prevent the bypass of selection pressure. In this study, however, the addition of glutamine did not affect cell population homogeneity, protein quality, or decrease antibody yield of two GS cell lines.

  5. Identifying the differences in mechanisms of mycophenolic acid controlling fucose content of glycoproteins expressed in different CHO cell lines.

    Science.gov (United States)

    Zhang, An; Tsang, Valerie Liu; Markely, Lam R; Kurt, Lutfiye; Huang, Yao-Ming; Prajapati, Shashi; Kshirsagar, Rashmi

    2016-11-01

    In the biopharmaceutical industry, glycosylation is a critical quality attribute that can modulate the efficacy of a therapeutic glycoprotein. Obtaining a consistent glycoform profile is desired because molecular function can be defined by its carbohydrate structures. Specifically, the fucose content of oligosaccharides in glycoproteins is one of the most important attributes that can significantly affect antibody-dependent cellular cytotoxicity (ADCC) activity. It is therefore important to understand the fucosylation pathway and be able to control fucosylation at the desired level to match predecessor materials in late stage and biosimilar programs. Several strategies were explored in this study and mycophenolic acid (MPA) was able to finely modulate the fucose content with the least undesired side effects. However, the response was significantly different between CHO cell lines of different lineages. Further experiments were then performed for a deeper understanding of the mechanism of fucosylation in different CHO cell lines. Results indicated that changes in the intracellular nucleotide involved in fucosylation pathway after MPA treatment are the main cause of the differences in fucosylation level response in different CHO cell lines. Differences in MPA metabolism in the various CHO cell lines directly resulted in different levels of afucosylation measured in antibodies produced by the CHO cell lines. Biotechnol. Bioeng. 2016;113: 2367-2376. © 2016 Wiley Periodicals, Inc.

  6. Verhulst and stochastic models for comparing mechanisms of MAb productivity in six CHO cell lines.

    Science.gov (United States)

    Shirsat, Nishikant; Avesh, Mohd; English, Niall J; Glennon, Brian; Al-Rubeai, Mohamed

    2016-08-01

    The present study validates previously published methodologies-stochastic and Verhulst-for modelling the growth and MAb productivity of six CHO cell lines grown in batch cultures. Cytometric and biochemical data were used to model growth and productivity. The stochastic explanatory models were developed to improve our understanding of the underlying mechanisms of growth and productivity, whereas the Verhulst mechanistic models were developed for their predictability. The parameters of the two sets of models were compared for their biological significance. The stochastic models, based on the cytometric data, indicated that the productivity mechanism is cell specific. However, as shown before, the modelling results indicated that G2 + ER indicate high productivity, while G1 + ER indicate low productivity, where G1 and G2 are the cell cycle phases and ER is Endoplasmic Reticulum. In all cell lines, growth proved to be inversely proportional to the cumulative G1 time (CG1T) for the G1 phase, whereas productivity was directly proportional to ER. Verhulst's rule, "the lower the intrinsic growth factor (r), the higher the growth (K)," did not hold for growth across all cell lines but held good for the cell lines with the same growth mechanism-i.e., r is cell specific. However, the Verhulst productivity rule, that productivity is inversely proportional to the intrinsic productivity factor (r x ), held well across all cell lines in spite of differences in their mechanisms for productivity-that is, r x is not cell specific. The productivity profile, as described by Verhulst's logistic model, is very similar to the Michaelis-Menten enzyme kinetic equation, suggesting that productivity is more likely enzymatic in nature. Comparison of the stochastic and Verhulst models indicated that CG1T in the cytometric data has the same significance as r, the intrinsic growth factor in the Verhulst models. The stochastic explanatory and the Verhulst logistic models can explain the

  7. Chemical inhibition of autophagy: Examining its potential to increase the specific productivity of recombinant CHO cell lines.

    Science.gov (United States)

    Baek, Eric; Kim, Che Lin; Kim, Mi Gyeom; Lee, Jae Seong; Lee, Gyun Min

    2016-09-01

    Chinese hamster ovary (CHO) cells activate and undergo apoptosis and autophagy for various environmental stresses. Unlike apoptosis, studies on increasing the production of therapeutic proteins in CHO cells by targeting the autophagy pathway are limited. In order to identify the effects of chemical autophagy inhibitors on the specific productivity (qp ), nine chemical inhibitors that had been reported to target three different phases of autophagy (metformin, dorsomorphin, resveratrol, and SP600125 against initiation and nucleation; 3-MA, wortmannin, and LY294002 against elongation, and chloroquine and bafilomycin A1 against autophagosome fusion) were used to treat three recombinant CHO (rCHO) cell lines: the Fc-fusion protein-producing DG44 (DG44-Fc) and DUKX-B11 (DUKX-Fc) and antibody-producing DG44 (DG44-Ab) cell lines. Among the nine chemical inhibitors tested, 3-MA, dorsomorphin, and SP600125 significantly increased the qp of DG44-Fc and DUKX-Fc. In contrast, for DG44-Ab, only 3-MA significantly increased the qp . The autophagy-inhibiting activity of the nine chemical inhibitors on the rCHO cell lines was evaluated through Western blot analysis and flow cytometry. Unexpectedly, some chemical inhibitors did not exhibit any apparent inhibition activity on autophagy. The chemical inhibitors that enhanced the qp , 3-MA, dorsomorphin, and SP600125, exhibited instead an increased autophagic flux. Taken all together, the chemical inhibition of autophagy was not effective in increasing the qp in rCHO cell lines and the positive effect of 3-MA, dorsomorphin, and SP600125 on the qp was not due to the inhibition of autophagy. Biotechnol. Bioeng. 2016;113: 1953-1961. © 2016 Wiley Periodicals, Inc.

  8. Creation of Tenecteplase-Producing CHO Cell Line Using Site-Specific Integrase from the Phage φC31

    OpenAIRE

    2010-01-01

    Objective: The aim of this study was to produce a stable CHO cell line expressing tenecteplase.Materials and Methods: In the first step, the tenecteplase coding sequence was clonedin a pDB2 vector containing attB recognition sites for the phage φC31 integrase. Then,using lipofection, the CHO cells were co-transfected with constructed recombinant plasmidencoding tenecteplase and attB recognition sites and the integrase coding sequencecontaining pCMV-Int plasmid. As the recombinant plasmid cont...

  9. Optimization of cell line development in the GS-CHO expression system using a high-throughput, single cell-based clone selection system.

    Science.gov (United States)

    Nakamura, Tsuyoshi; Omasa, Takeshi

    2015-09-01

    Therapeutic antibodies are commonly produced by high-expressing, clonal and recombinant Chinese hamster ovary (CHO) cell lines. Currently, CHO cells dominate as a commercial production host because of their ease of use, established regulatory track record, and safety profile. CHO-K1SV is a suspension, protein-free-adapted CHO-K1-derived cell line employing the glutamine synthetase (GS) gene expression system (GS-CHO expression system). The selection of high-producing mammalian cell lines is a crucial step in process development for the production of therapeutic antibodies. In general, cloning by the limiting dilution method is used to isolate high-producing monoclonal CHO cells. However, the limiting dilution method is time consuming and has a low probability of monoclonality. To minimize the duration and increase the probability of obtaining high-producing clones with high monoclonality, an automated single cell-based clone selector, the ClonePix FL system, is available. In this study, we applied the high-throughput ClonePix FL system for cell line development using CHO-K1SV cells and investigated efficient conditions for single cell-based clone selection. CHO-K1SV cell growth at the pre-picking stage was improved by optimizing the formulation of semi-solid medium. The efficiency of picking and cell growth at the post-picking stage was improved by optimization of the plating time without decreasing the diversity of clones. The conditions for selection, including the medium formulation, were the most important factors for the single cell-based clone selection system to construct a high-producing CHO cell line.

  10. Creation of Tenecteplase-Producing CHO Cell Line Using Site-Specific Integrase from the Phage φC31

    Directory of Open Access Journals (Sweden)

    Khadijeh Karbalaie

    2010-01-01

    Full Text Available Objective: The aim of this study was to produce a stable CHO cell line expressing tenecteplase.Materials and Methods: In the first step, the tenecteplase coding sequence was clonedin a pDB2 vector containing attB recognition sites for the phage φC31 integrase. Then,using lipofection, the CHO cells were co-transfected with constructed recombinant plasmidencoding tenecteplase and attB recognition sites and the integrase coding sequencecontaining pCMV-Int plasmid. As the recombinant plasmid contained the neomycin resistancegene (neo, stable cells were then selected using G418 as an antibiotic. Stabletransformed cells were assessed using genomic PCR and RT-PCR. Finally, the functionalityof tenecteplase was evaluated on the cell culture media.Results: our results indicated that tenecteplase coding sequence was inserted into theCHO cell genome and was successfully expressed. Moreover, tenecteplase activity assessmentindicated the presence of our functional tenecteplase in the cell culture medium.Conclusion: Considering the data obtained from this study, φC31 integrase can be usedfor the production of a stable cell line and it be used to introduce ectopic genes into mammaliancells.

  11. CHO-S Antibody Titers >1 Gram/Liter Using Flow Electroporation-Mediated Transient Gene Expression followed by Rapid Migration to High-Yield Stable Cell Lines

    OpenAIRE

    Steger, Krista; Brady, James; WANG, WEILI; Duskin, Meg; Donato, Karen; Peshwa, Madhusudan

    2015-01-01

    In recent years, researchers have turned to transient gene expression (TGE) as an alternative to CHO stable cell line generation for early-stage antibody development. Despite advances in transfection methods and culture optimization, the majority of CHO-based TGE systems produce insufficient antibody titers for extensive use within biotherapeutic development pipelines. Flow electroporation using the MaxCyte STX Scalable Transfection System is a highly efficient, scalable means of CHO-based TG...

  12. CHO-S antibody titers >1 gram/liter using flow electroporation-mediated transient gene expression followed by rapid migration to high-yield stable cell lines.

    Science.gov (United States)

    Steger, Krista; Brady, James; Wang, Weili; Duskin, Meg; Donato, Karen; Peshwa, Madhusudan

    2015-04-01

    In recent years, researchers have turned to transient gene expression (TGE) as an alternative to CHO stable cell line generation for early-stage antibody development. Despite advances in transfection methods and culture optimization, the majority of CHO-based TGE systems produce insufficient antibody titers for extensive use within biotherapeutic development pipelines. Flow electroporation using the MaxCyte STX Scalable Transfection System is a highly efficient, scalable means of CHO-based TGE for gram-level production of antibodies without the need for specialized expression vectors or genetically engineered CHO cell lines. CHO cell flow electroporation is easily scaled from milligram to multigram quantities without protocol reoptimization while maintaining transfection performance and antibody productivity. In this article, data are presented that demonstrate the reproducibility, scalability, and antibody production capabilities of CHO-based TGE using the MaxCyte STX. Data show optimization of posttransfection parameters such as cell density, media composition, and feed strategy that result in secreted antibody titers >1 g/L and production of multiple grams of antibody within 2 weeks of a single CHO-S cell transfection. In addition, data are presented to demonstrate the application of scalable electroporation for the rapid generation of high-yield stable CHO cell lines to bridge the gap between early- and late-stage antibody development activities.

  13. A high cell density transient transfection system for therapeutic protein expression based on a CHO GS-knockout cell line: process development and product quality assessment.

    Science.gov (United States)

    Rajendra, Yashas; Hougland, Maria D; Alam, Riazul; Morehead, Teresa A; Barnard, Gavin C

    2015-05-01

    Transient gene expression (TGE) is a rapid method for the production of recombinant proteins in mammalian cells. While the volumetric productivity of TGE has improved significantly over the past decade, most methods involve extensive cell line engineering and plasmid vector optimization in addition to long fed batch cultures lasting up to 21 days. Our colleagues have recently reported the development of a CHO K1SV GS-KO host cell line. By creating a bi-allelic glutamine synthetase knock out of the original CHOK1SV host cell line, they were able to improve the efficiency of generating high producing stable CHO lines for drug product manufacturing. We developed a TGE method using the same CHO K1SV GS-KO host cell line without any further cell line engineering. We also refrained from performing plasmid vector engineering. Our objective was to setup a TGE process to mimic protein quality attributes obtained from stable CHO cell line. Polyethyleneimine (PEI)-mediated transfections were performed at high cell density (4 × 10(6) cells/mL) followed by immediate growth arrest at 32 °C for 7 days. Optimizing DNA and PEI concentrations proved to be important. Interestingly, found the direct transfection method (where DNA and PEI were added sequentially) to be superior to the more common indirect method (where DNA and PEI are first pre-complexed). Moreover, the addition of a single feed solution and a polar solvent (N,N dimethylacetamide) significantly increased product titers. The scalability of process from 2 mL to 2 L was demonstrated using multiple proteins and multiple expression volumes. Using this simple, short, 7-day TGE process, we were able to successfully produce 54 unique proteins in a fraction of the time that would have been required to produce the respective stable CHO cell lines. The list of 54 unique proteins includes mAbs, bispecific antibodies, and Fc-fusion proteins. Antibody titers of up to 350 mg/L were achieved with the simple 7-day process. Titers

  14. Recombination activating activity of XRCC1 analogous genes in X-ray sensitive and resistant CHO cell lines

    Science.gov (United States)

    Golubnitchaya-Labudová, O.; Portele, A.; Vaçata, V.; Lubec, G.; Rink, H.; Höfer, M.

    1997-10-01

    The XRCC1 gene (X-ray repair cross complementing) complements the DNA repair deficiency of the radiation sensitive Chinese hamster ovary (CHO) mutant cell line EM9 but the mechanism of the correction is not elucidated yet. XRCC1 shows substantial homology to the RAG2 gene (recombination activating gene) and we therefore tried to answer question, whether structural similarities (sequence of a putative recombination activating domain, aa 332-362 for XRCC1 and aa 286-316 in RAG2) would reflect similar functions of the homologous, putative recombination activating domain. PCR experiments revealed that no sequence homologous to the structural part of human XRCC1 was present in cDNA of CHO. Differential display demonstrated two putative recombination activating domains in the parental CHO line AA8 and one in the radiosensitive mutant EM9. Southern blot experiments showed the presence of several genes with partial homology to human XRCC1. Recombination studies consisted of expressing amplified target domains within chimeric proteins in recA - bacteria and subsequent detection of recombination events by sequencing the recombinant plasmids. Recombination experiments demonstrated recombination activating activity of all putative recombination activating domains amplified from AA8 and EM9 genomes as reflected by deletions within the insert of the recombinant plasmids. The recombination activating activity of XRCC1 analogues could explain a mechanism responsible for the correction of the DNA repair defect in EM9.

  15. Eliminating tyrosine sequence variants in CHO cell lines producing recombinant monoclonal antibodies.

    Science.gov (United States)

    Feeney, Lauren; Carvalhal, Veronica; Yu, X Christopher; Chan, Betty; Michels, David A; Wang, Yajun Jennifer; Shen, Amy; Ressl, Jan; Dusel, Brendon; Laird, Michael W

    2013-04-01

    Amino acid sequence variants are defined as unintended amino acid sequence changes that contribute to product variation with potential impact to product safety, immunogenicity, and efficacy. Therefore, it is important to understand the propensity for sequence variant (SV) formation during the production of recombinant proteins for therapeutic use. During the development of clinical therapeutic products, several monoclonal antibodies (mAbs) produced from Chinese Hamster Ovary (CHO) cells exhibited SVs at low levels (≤3%) in multiple locations throughout the mAbs. In these examples, the cell culture process depleted tyrosine, and the tyrosine residues in the recombinant mAbs were replaced with phenylalanine or histidine. In this work, it is demonstrated that tyrosine supplementation eliminated the tyrosine SVs, while early tyrosine starvation significantly increased the SV level in all mAbs tested. Additionally, it was determined that phenylalanine is the amino acid preferentially misincorporated in the absence of tyrosine over histidine, with no other amino acid misincorporated in the absence of tyrosine, phenylalanine, and histidine. The data support that the tyrosine SVs are due to mistranslation and not DNA mutation, most likely due to tRNA(Tyr) mischarging due to the structural similarities between tyrosine and phenylalanine.

  16. One-step generation of triple knockout CHO cell lines using CRISPR/Cas9 and fluorescent enrichment

    DEFF Research Database (Denmark)

    Grav, Lise Marie; Lee, Jae Seong; Thomsen, Signe Gerling

    2015-01-01

    The CRISPR/Cas9 genome editing technology has previously been shown to be a highly efficient tool for generating gene disruptions in CHO cells. In this study we further demonstrate the applicability and efficiency of CRISPR/Cas9 genome editing by disrupting FUT8, BAK and BAX simultaneously....... Taken together, multiplexing with CRISPR/Cas9 can accelerate genome engineering efforts in CHO cells even further....

  17. Combined 5-FU and ChoKα inhibitors as a new alternative therapy of colorectal cancer: evidence in human tumor-derived cell lines and mouse xenografts.

    Directory of Open Access Journals (Sweden)

    Ana de la Cueva

    Full Text Available BACKGROUND: Colorectal cancer (CRC is the third major cause of cancer related deaths in the world. 5-fluorouracil (5-FU is widely used for the treatment of colorectal cancer but as a single-agent renders low response rates. Choline kinase alpha (ChoKα, an enzyme that plays a role in cell proliferation and transformation, has been reported overexpressed in many different tumors, including colorectal tumors. ChoKα inhibitors have recently entered clinical trials as a novel antitumor strategy. METHODOLOGY/PRINCIPAL FINDINGS: ChoKα specific inhibitors, MN58b and TCD-717, have demonstrated a potent antitumoral activity both in vitro and in vivo against several tumor-derived cell line xenografts including CRC-derived cell lines. The effect of ChoKα inhibitors in combination with 5-FU as a new alternative for the treatment of colon tumors has been investigated both in vitro in CRC-tumour derived cell lines, and in vivo in mouse xenografts models. The effects on thymidilate synthase (TS and thymidine kinase (TK1 levels, two enzymes known to play an essential role in the mechanism of action of 5-FU, were analyzed by western blotting and quantitative PCR analysis. The combination of 5-FU with ChoKα inhibitors resulted in a synergistic effect in vitro in three different human colon cancer cell lines, and in vivo against human colon xenografts in nude mice. ChoKα inhibitors modulate the expression levels of TS and TK1 through inhibition of E2F production, providing a rational for its mechanism of action. CONCLUSION/SIGNIFICANCE: Our data suggest that both drugs in combination display a synergistic antitumoral effect due to ChoKα inhibitors-driven modulation of the metabolization of 5-FU. The clinical relevance of these findings is strongly supported since TCD-717 has recently entered Phase I clinical trials against solid tumors.

  18. Cytoskeleton, endoplasmic reticulum and nucleus alterations in CHO-K1 cell line after Crotalus durissus terrificus (South American rattlesnake venom treatment

    Directory of Open Access Journals (Sweden)

    B. P. Tamieti

    2007-01-01

    Full Text Available Snake venoms are toxic to a variety of cell types. However, the intracellular damages and the cell death fate induced by venom are unclear. In the present work, the action of the South American rattlesnake Crotalus durissus terrificus venom on CHO-K1 cell line was analyzed. The cells CHO-K1 were incubated with C. d. terrificus venom (10, 50 and 100g/ml for 1 and 24 hours, and structural alterations of actin filaments, endoplasmic reticulum and nucleus were assessed using specific fluorescent probes and agarose gel electrophoresis for DNA fragmentation. Significant structural changes were observed in all analyzed structures. DNA fragmentation was detected suggesting that, at the concentrations used, the venom induced apoptosis.

  19. A bovine papillomavirus-1 based vector restores the function of the low-density lipoprotein receptor in the receptor-deficient CHO-ldlA7 cell line

    Directory of Open Access Journals (Sweden)

    Ustav Mart

    2002-04-01

    Full Text Available Abstract Background The rationale of using bovine papillomavirus-1 (BPV-1 derived vectors in gene therapy protocols lies in their episomal maintenance at intermediate to high copy number, and stable, high-level expression of the gene products. We constructed the BPV-1 based vector harbouring the human low-density lipoprotein receptor (LDLR gene cDNA and tested its ability to restore the function of the LDLR in the receptor-deficient cell line CHO-ldlA7. Results The introduced vector p3.7LDL produced functionally active LDL receptors in the receptor-deficient cell line CHO-ldlA7 during the 32-week period of observation as determined by the internalisation assay with the labelled LDL particles. Conclusion Bovine papillomavirus type-1 (BPV-1-derived vectors could be suitable for gene therapy due to their episomal maintenance at intermediate to high copy number and stable, high-level expression of the gene products. The constructed BPV-1 based vector p3.7LDL produced functionally active LDL receptors in the LDLR-deficient cell line CHO-ldlA7 during the 32-week period of observation. In vivo experiments should reveal, whether 1–5% transfection efficiency obtained in the current work is sufficient to bring about detectable and clinically significant lowering of the amount of circulating LDL cholesterol particles.

  20. Quantitative definition and monitoring of the host cell protein proteome using iTRAQ - a study of an industrial mAb producing CHO-S cell line.

    Science.gov (United States)

    Chiverton, Lesley M; Evans, Caroline; Pandhal, Jagroop; Landels, Andrew R; Rees, Byron J; Levison, Peter R; Wright, Phillip C; Smales, C Mark

    2016-08-01

    There are few studies defining CHO host cell proteins (HCPs) and the flux of these throughout a downstream purification process. Here we have applied quantitative iTRAQ proteomics to follow the HCP profile of an antibody (mAb) producing CHO-S cell line throughout a standard downstream purification procedure consisting of a Protein A, cation and anion exchange process. We used both 6 sample iTRAQ experiment to analyze technical replicates of three samples, which were culture harvest (HCCF), Protein A flow through and Protein A eluate and an 8 sample format to analyze technical replicates of four sample types; HCCF compared to Protein A eluate and subsequent cation and anion exchange purification. In the 6 sample iTRAQ experiment, 8781 spectra were confidently matched to peptides from 819 proteins (including the mAb chains). Across both the 6 and 8 sample experiments 936 proteins were identified. In the 8 sample comparison, 4187 spectra were confidently matched to peptides from 219 proteins. We then used the iTRAQ data to enable estimation of the relative change of individual proteins across the purification steps. These data provide the basis for application of iTRAQ for process development based upon knowledge of critical HCPs.

  1. Sustained productivity in recombinant Chinese Hamster Ovary (CHO) cell lines: proteome analysis of the molecular basis for a process-related phenotype

    LENUS (Irish Health Repository)

    Meleady, Paula

    2011-07-24

    Abstract Background The ability of mammalian cell lines to sustain cell specific productivity (Qp) over the full duration of bioprocess culture is a highly desirable phenotype, but the molecular basis for sustainable productivity has not been previously investigated in detail. In order to identify proteins that may be associated with a sustained productivity phenotype, we have conducted a proteomic profiling analysis of two matched pairs of monoclonal antibody-producing Chinese hamster ovary (CHO) cell lines that differ in their ability to sustain productivity over a 10 day fed-batch culture. Results Proteomic profiling of inherent differences between the two sets of comparators using 2D-DIGE (Difference Gel Electrophoresis) and LC-MS\\/MS resulted in the identification of 89 distinct differentially expressed proteins. Overlap comparisons between the two sets of cell line pairs identified 12 proteins (AKRIB8, ANXA1, ANXA4, EIF3I, G6PD, HSPA8, HSP90B1, HSPD1, NUDC, PGAM1, RUVBL1 and CNN3) that were differentially expressed in the same direction. Conclusion These proteins may have an important role in sustaining high productivity of recombinant protein over the duration of a fed-batch bioprocess culture. It is possible that many of these proteins could be useful for future approaches to successfully manipulate or engineer CHO cells in order to sustain productivity of recombinant protein.

  2. Isolation of the serotoninergic 5-HT4(e) receptor from human heart and comparative analysis of its pharmacological profile in C6-glial and CHO cell lines

    Science.gov (United States)

    Mialet, Jeanne; Berque-Bestel, Isabelle; Eftekhari, Pierre; Gastineau, Monique; Giner, Mireille; Dahmoune, Yamina; Donzeau-Gouge, Patrick; Hoebeke, Johan; Langlois, Michel; Sicsic, Sames; Fischmeister, Rodolphe; Lezoualc'h, Frank

    2000-01-01

    RT–PCR technique was used to clone the human 5-HT4(e) receptor (h5-HT4(e)) from heart atrium. We showed that this h5-HT4(e) receptor splice variant is restricted to brain and heart atrium. Recombinant h5-HT4(e) receptor was stably expressed in CHO and C6-glial cell lines at 347 and 88 fmol mg−1 protein, respectively. Expression of h5-HT4(e) receptors at the cell membrane was confirmed by immunoblotting. The receptor binding profile, determined by competition with [3H]-GR113808 of a number of 5-HT4 ligands, was consistent with that previously reported for other 5-HT4 receptor isoforms. Surprisingly, we found that the rank order of potencies (EC50) of 5-HT4 agonists obtained from adenylyl cyclase functional assays was inversely correlated to their rank order of affinities (Ki) obtained from binding assays. Furthermore, EC50 values for 5-HT, renzapride and cisapride were 2 fold lower in C6-glial cells than in CHO cells. ML10302 and renzapride behaved like partial agonists on the h5-HT4(e) receptor. These results are in agreement with the reported low efficacy of the these two compounds on L-type Ca2+ currents and myocyte contractility in human atrium. A constitutive activity of the h5-HT4(e) receptor was observed in CHO cells in the absence of any 5-HT4 ligand and two 5-HT4 antagonists, GR113808 and ML10375, behaved as inverse agonists. These data show that the h5-HT4(e) receptor has a pharmacological profile which is close to the native h5-HT4 receptor in human atrium with a functional potency which is dependent on the cellular context in which the receptor is expressed. PMID:10683202

  3. Evaluating the impact of high Pluronic® F68 concentrations on antibody producing CHO cell lines.

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    Tharmalingam, Tharmala; Goudar, Chetan T

    2015-04-01

    Pluronic® F68 (P-F68) is an important component of chemically-defined cell culture medium because it protects cells from hydrodynamic and bubble-induced shear in the bioreactor. While P-F68 is typically used in cell culture medium at a concentration of 1 g/L (0.1%), higher concentrations can offer additional shear protection and have also been shown to be beneficial during cryopreservation. Recent industry experience with variability in P-F68-associated shear-protection has opened up the possibility of elevated P-F68 concentrations in cell culture media, a topic that has not been previously explored in the context of industrial cell culture processes. Recognizing this gap, we first evaluated the effect of 1-5 g/L P-F68 concentrations in shake flask cultures over ten 3-day passages for cell lines A and B. Increase in terminal cell density and cell size was seen over time at higher P-F68 concentrations but protein productivity was not impacted. Results from this preliminary screening study suggested no adverse impact of high P-F68 concentrations. Subsequently fed-batch bioreactor experiments were conducted at 1 and 5 g/L P-F68 concentrations with both cell lines where cell growth, viability, metabolism, and product quality were examined under process conditions reflective of a commercial process. Results from these bioreactor experiments confirmed findings from the preliminary screen and also indicated no impact of elevated P-F68 concentration on product quality. If additional shear protection is desired, either due to raw material variability, cell line sensitivity, or a high-shear cell culture process, our results suggest this can be accomplished by elevating the P-F68 concentration in the cell culture medium without impacting cell culture performance and product quality.

  4. Multifrequency permittivity measurements enable on-line monitoring of changes in intracellular conductivity due to nutrient limitations during batch cultivations of CHO cells.

    Science.gov (United States)

    Ansorge, Sven; Esteban, Geoffrey; Schmid, Georg

    2010-01-01

    Lab and pilot scale batch cultivations of a CHO K1/dhfr(-) host cell line were conducted to evaluate on-line multifrequency permittivity measurements as a process monitoring tool. The beta-dispersion parameters such as the characteristic frequency (f(C)) and the permittivity increment (Deltaepsilon(max)) were calculated on-line from the permittivity spectra. The dual-frequency permittivity signal correlated well with the off-line measured biovolume and the viable cell density. A significant drop in permittivity was monitored at the transition from exponential growth to a phase with reduced growth rate. Although not reflected in off-line biovolume measurements, this decrease coincided with a drop in OUR and was probably caused by the depletion of glutamine and a metabolic shift occurring at the same time. Sudden changes in cell density, cell size, viability, capacitance per membrane area (C(M)), and effects caused by medium conductivity (sigma(m)) could be excluded as reasons for the decrease in permittivity. After analysis of the process data, a drop in f(C) as a result of a fall in intracellular conductivity (sigma(i)) was identified as responsible for the observed changes in the dual-frequency permittivity signal. It is hypothesized that the beta-dispersion parameter f(C) is indicative of changes in nutrient availability that have an impact on intracellular conductivity sigma(i). On-line permittivity measurements consequently not only reflect the biovolume but also the physiological state of mammalian cell cultures. These findings should pave the way for a better understanding of the intracellular state of cells and render permittivity measurements an important tool in process development and control.

  5. RNA-seq based expression analysis of the CHO cell protein secretion pathway

    DEFF Research Database (Denmark)

    Lund, Anne Mathilde; Kaas, Christian Schrøder; Kildegaard, Helene Faustrup;

    The Chinese hamster ovary (CHO) cell-line is the predominant mammalian industrial cell line being used to produce recombinant therapeutic proteins. Although CHO cells have been used for more than 25 years, the genome sequence was first published in 2011. So far there have been limited studies...

  6. The indirect effect of radiation reduces the repair fidelity of NHEJ as verified in repair deficient CHO cell lines exposed to different radiation qualities and potassium bromate

    Energy Technology Data Exchange (ETDEWEB)

    Bajinskis, Ainars, E-mail: ainars.bajinskis@gmt.su.se [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden); Olsson, Gunilla; Harms-Ringdahl, Mats [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden)

    2012-03-01

    The complexity of DNA lesions induced by ionizing radiation is mainly dependent on radiation quality, where the indirect action of radiation may contribute to different extent depending on the type of radiation under study. The effect of indirect action of radiation can be investigated by using agents that induce oxidative DNA damage or by applying free radical scavengers. The aim of this study was to investigate the role of the indirect effect of radiation for the repair fidelity of non-homologous end-joining (NHEJ), homologous recombination repair (HRR) and base excision repair (BER) when DNA damage of different complexity was induced by gamma radiation, alpha particles or from base damages (8-oxo-dG) induced by potassium bromate (KBrO{sub 3}). CHO cells lines deficient in XRCC3 (HRR) irs1SF, XRCC7 (NHEJ) V3-3 and XRCC1 (BER) EM9 were irradiated in the absence or presence of the free radical scavenger dimethyl sulfoxide (DMSO). The endpoints investigated included rate of cell proliferation by the DRAG assay, clonogenic cell survival and the level of primary DNA damage by the comet assay. The results revealed that the indirect effect of low-LET radiation significantly reduced the repair fidelity of both NHEJ and HRR pathways. For high-LET radiation the indirect effect of radiation also significantly reduced the repair fidelity for the repair deficient cell lines. The results suggest further that the repair fidelity of the error prone NHEJ repair pathway is more impaired by the indirect effect of high-LET radiation relative to the other repair pathways studied. The response to bromate observed for the two DSB repair deficient cell lines strongly support earlier studies that bromate induces complex DNA damages. The significantly reduced repair fidelity of irs1SF and V3-3 suggests that NHEJ as well as HRR are needed for the repair, and that complex DSBs are formed after bromate exposure.

  7. Heparin promotes suspension adaptation process of CHO-TS28 cells by eliminating cell aggregation.

    Science.gov (United States)

    Li, Ling; Qin, Jun; Feng, Qiang; Tang, Hao; Liu, Rong; Xu, Liqing; Chen, Zhinan

    2011-01-01

    While heparin has been shown to eliminate cell aggregation in suspension adaptations of insect and HEK293 cells for virus-based cell cultures, the role of heparin in long period serum-free suspension adaptation of the anchorage-dependent Chinese hamster ovary (CHO) cell lines remains inconclusive. In this paper, we explore the potential application of heparin in suspension adaptation of CHO cell line which produces an anti-human chimeric antibody cHAb18. Heparin showed a concentration-dependent inhibition of CHO-TS28 cell-to-cell adhesion, with a significant inhibitory effect occurring when the concentration exceeded 250 μg/ml (P cell aggregation elimination role at all concentrations (P cell growth and antibody secretion, with the highest cell density ((99.83 ± 12.21) × 10(4) cells/ml, P = 0.034) and maximum antibody yield ((9.46 ± 0.94) mg/l, P cell aggregates were effectively dispersed by 250 μg/ml heparin and a single-cell suspension culture process was promoted. In suspension adapted CHO-TS28 cells, cell growth rates and specific antibody productivity were maintained; while antigen-binding activity improved slightly. Together, our results show that heparin may promote suspension adaptation of anchorage-depended CHO cells by resisting cell aggregation without reducing cell growth, antibody secretion, and antigen-binding activity.

  8. CYP3A4 overexpression enhances the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in CHO cells

    Institute of Scientific and Technical Information of China (English)

    Ewa AUGUSTIN; Barbara BOROWA-MAZGAJ; Agnieszka KIKULSKA; Milena KORDALEWSKA; Monika PAW(L)OWS KA

    2013-01-01

    Aim:To examine how the higher expression level of CYP3A4 isoenzyme influenced the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in Chinese hamster ovary (CHO) cells.Methods:Three CHO cell lines were examined:wild-type CHO cells; CHO-HR cells with overexpression of human cytochrome P450 reductase (CPR); and CHO-HR-3A4 cells with coexpression of human CYP3A4 and CPR.Cellular responses caused by C-1305 were monitored using DAPI staining,cell cycle analysis,phosphatydilserine externalization analysis and SA-β-galactosidase expression analysis.Cell viability was assessed with simultaneous FDA and PI staining.Results:Treatment with C-1305 for 72 h exhibited different levels of cytotoxicity in the 3 cell lines,and the values of IC80 in CHO,CHO-HR and CHO-HR-3A4 cells were 0.087+0.005,0.032+0.0001,and 0.064+0.0095 μmol/L,respectively.The cell cycle analysis revealed that both CHO and CHO-HR cells underwent transient G2/M arrest,whereas CHO-HR-3A4 cells did not accumulate in this phase.Prolonged exposure up to 120 h caused time-dependent increase in the sub-G1 fraction in all the 3 cell lines.Treatment with C-1305 caused cell death through apoptosis and necrosis.However,these processes were more pronounced in the transfected CHO cells than in the wild-type cells.The cells surviving after C-1305 exposure underwent senescence.Conclusion:CYP3A4 overexpression potently enhances the cellular responses (apoptosis,necrosis and senescence) caused by C-1305 in CHO cells.

  9. 小鼠pEGFP-Hoxa11真核表达载体的构建及表达%Construction of pEGFP-Hoxa11 Eukaryotic Expression Vector and Its Expression in CHO Cell Line

    Institute of Scientific and Technical Information of China (English)

    熊敏; 于倩; 崔爱娜; 张力; 朱桂金

    2011-01-01

    目的 构建和鉴定Hoxa11和EGFP双基因共表达真核载体.方法 采用DNA重组技术,将目的 基因Hoxa11克隆至含有报告基因EGFP的pEGFP-N1真核表达载体中,构建的真核表达载体pEGFP-Hoxa11经PCR,双酶切及基因测序鉴定;转染至CHO细胞,荧光显微镜下观察重组质粒的表达,提取细胞蛋白Western印迹检测蛋白表达.结果 pEGFP-Hoxa11重组质粒构建成功.构建的真核表达载体pEGFP-Hoxa11能在CHO细胞中有效表达.结论 成功构建了共表达Hoxa11和EGFP的真核表达载体,并能在CHO细胞中有效表达.为进一步研究Hoxa11的功能提供实验基础.%Objective To construct the recombinant plasmid pEGFP-Hoxa11 and detect its expression in CHO cell line. Methods The fragments of Hoxa11 was produced by PCR. After enzyme digestion by EcoRI and KpnI, the digested fragments were ligated into pEGFP vector overnight by T4 DNA ligase. The insertion of Hoxa11 in the recombinant plasmid of pEGFP-Hoxa11 was confirmed by PCR, enzyme digestion and DNA sequencing. The recombinant pEGFP-Hoxa11 was transfected into CHO cell lines. and EGFP-Hoxa11 expression was detected by fluorescence microscope and Western blotting analysis. Results The recombinant plasmid pEGFP-Hoxa11 was successfully constructed and its expression was visible in the transfected CHO cells under fluorescence microscope, and Hoxa11 expression was significantly increased in pEGFP-Hoxa11 transfection compared to the endogenous Hoxa11 level in empty vector transfected CHO cells. Conclusion The expression vector pEGFP-Hoxa11 was successfully constructed to co-express Hoxa11 and EGFP protein in CHO cell line.

  10. Producing recombinant therapeutic glycoproteins with enhanced sialylation using CHO-gmt4 glycosylation mutant cells

    Science.gov (United States)

    Goh, John SY; Liu, Yingwei; Chan, Kah Fai; Wan, Corrine; Teo, Gavin; Zhang, Peiqing; Zhang, Yuanxing; Song, Zhiwei

    2014-01-01

    Recombinant glycoprotein drugs require proper glycosylation for optimal therapeutic efficacy. Glycoprotein therapeutics are rapidly removed from circulation and have reduced efficacy if they are poorly sialylated. Ricinus communis agglutinin-I (RCA-I) was found highly toxic to wild-type CHO-K1 cells and all the mutants that survived RCA-I treatment contained a dysfunctional N-acetylglucosaminyltransferase I (GnT I) gene. These mutants are named CHO-gmt4 cells. Interestingly, upon restoration of GnT I, the sialylation of a model glycoprotein, erythropoietin, produced in CHO-gmt4 cells was shown to be superior to that produced in wild-type CHO-K1 cells. This addendum summarizes the applicability of this cell line, from transient to stable expression of the recombinant protein, and from a lab scale to an industrial scale perfusion bioreactor. In addition, CHO-gmt4 cells can be used to produce glycoproteins with mannose-terminated N-glycans. Recombinant glucocerebrosidase produced by CHO-gmt4 cells will not require glycan remodeling and may be directly used to treat patients with Gaucher disease. CHO-gmt4 cells can also be used to produce other glycoprotein therapeutics which target cells expressing mannose receptors. PMID:24911584

  11. Comparison of protein patterns of xrs-5, a radiosensitive Chinese hamster ovary cell line, and CHO-K1, its radioresistant parent, using two-dimensional gel-electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, J.M. (Miami Univ., Oxford, OH (USA). Dept. of Zoology)

    1991-01-01

    X-ray sensitive strains of Chinese hamster ovary cell lines have been used to analyze radiation repair mechanisms. One cell line, xrs-5, has been shown to be very sensitive to ionizing radiation and radical forming chemical mutagens. This sensitivity is thought to be a result a mutation in the DNA double strand break (DSB) repair mechanism, and its characterization has been a goal of several repair mechanism studies. Using two-dimensional gel electrophoresis, we have detected a protein (MW approximately 55KD) in the DNA/Nuclear Matrix (nucleoid) cell fraction of CHO-Kl cells that is absent in the nucleoid fraction of xrs-5. This protein is present, however, in both CHO-Kl and xrs-5 whole cell protein maps. To determine whether the 55KD protein is responsible for the radiosensitive and defective DSB repair phenotype of xrs-5 cells, studies are now underway to analyze revertants of xrs-5 that are proficient in DSB repair. Furthermore, an effort to sequence the protein in question is planned. 23 refs., 2 figs.

  12. Toward stable gene expression in CHO cells

    Science.gov (United States)

    Mariati; Koh, Esther YC; Yeo, Jessna HM; Ho, Steven CL; Yang, Yuansheng

    2014-01-01

    Maintaining high gene expression level during long-term culture is critical when producing therapeutic recombinant proteins using mammalian cells. Transcriptional silencing of promoters, most likely due to epigenetic events such as DNA methylation and histone modifications, is one of the major mechanisms causing production instability. Previous studies demonstrated that the core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene is effective to prevent DNA methylation. We generated one set of modified human cytomegalovirus (hCMV) promoters by insertion of one or two copies of IE in either forward or reverse orientations into different locations of the hCMV promoter. The modified hCMV with one copy of IE inserted between the hCMV enhancer and core promoter in reverse orientation (MR1) was most effective at enhancing expression stability in CHO cells without comprising expression level when compared with the wild type hCMV. We also found that insertion of IE into a chimeric murine CMV (mCMV) enhancer and human elongation factor-1α core (hEF) promoter in reverse orientation did not enhance expression stability, indicating that the effect of IE on expression stability is possibly promoter specific. PMID:25482237

  13. 人血小板生成素基因的克隆及CHO稳定细胞系的建立%Cloning of Human Thrombopoietin Gene and Establishment of CHO Cell Lines Stably Expressing TPO Gene

    Institute of Scientific and Technical Information of China (English)

    马倩倩; 宋玲玲; 王红梅; 方永志; 王立群; 何洪彬

    2013-01-01

    以人肝cDNA为模板克隆了人血小板生成素(Human Thrombopoietin,hTPO)基因,利用基因重组技术构建了带有新霉素抗性基因(neo)筛选标记的pcDNA3.1(+)-hTPO真核表达载体,将重组质粒瞬时转染293T细胞,用鼠抗人TPO单抗Western blot检测TPO蛋白的瞬时表达;再将重组质粒转染中国仓鼠卵巢细胞(Chinese Hamster Ovary,CHO),应用400 μg/mL的G418筛选克隆,经PCR及Western blot验证,获得了3株hTPO蛋白表达水平不同的CHO细胞系,为获得大量蛋白并进行活性功能试验及临床应用奠定基础.%Human thrombopoietin (Human Thrombopoietin, hTPO) gene was cloned by PCR using the human liver cDNA as template, then fragment of hTPO gene was cloned into pcDNA3. 1 ( + ) eukaryotic expression vector which has the neomycin resistance gene (neo) selection marker, named as pcDNA3. 1 ( + )-hTPO. First, the recombinant plasmid was transiently transfected into 293T cells. The transient expression of TPO in eukaryotic cells was determined by Western blot using mouse anti-human TPO monoclonal antibody; then Chinese hamster ovary cells (Chinese hamster ovary, CHO) were transfected with pcDNA3. 1 ( + ) -hTPO recombinant plasmid, using G418 of 400 jug/ml to select CHO stable cell lines, and verified by PCR and Western blot. The above results showed that three CHO cell lines stably expressing TPO gene were established. The cell lines may get a large number of proteins applied to actual medical and activity functional experiments and even laid a certain foundation for the next stage.

  14. CRISPR/Cas9-mediated genome engineering of CHO cell factories: Application and perspectives.

    Science.gov (United States)

    Lee, Jae Seong; Grav, Lise Marie; Lewis, Nathan E; Faustrup Kildegaard, Helene

    2015-07-01

    Chinese hamster ovary (CHO) cells are the most widely used production host for therapeutic proteins. With the recent emergence of CHO genome sequences, CHO cell line engineering has taken on a new aspect through targeted genome editing. The bacterial clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system enables rapid, easy and efficient engineering of mammalian genomes. It has a wide range of applications from modification of individual genes to genome-wide screening or regulation of genes. Facile genome editing using CRISPR/Cas9 empowers researchers in the CHO community to elucidate the mechanistic basis behind high level production of proteins and product quality attributes of interest. In this review, we describe the basis of CRISPR/Cas9-mediated genome editing and its application for development of next generation CHO cell factories while highlighting both future perspectives and challenges. As one of the main drivers for the CHO systems biology era, genome engineering with CRISPR/Cas9 will pave the way for rational design of CHO cell factories.

  15. Prediction and cloning linear Tcell epitopes of P14-3-3 antigen into pEGFP–N1 as a DNA vaccine model to induse immuno response against hydatidosis and it\\'s expression in CHO cell line

    Directory of Open Access Journals (Sweden)

    R mesri

    2015-11-01

    Full Text Available ABSTRACT Background & purpose: Hydatidosis is a zoonotic disease that caused by infection with the larvae of Echinococcus granulosus. Different antigens produced in larval stage of this parasite that recombinant vaccine base these antigens created significant immunity in infected animals. One of the important antigens is p14-3-3 that it's recombinant antigen created considerable immunity in mouse models. In this study according to the high immunity of antigen epitopes region the coding sequence of T-cell epitopes of P14-3-3 was cloned into pEGFP-N1vector in order to produce an effective DNA vaccine model to stimulate high level of Th1 immune response.   Material and method: In this study bioinformatics tools were used to prediction of linear T-Cell epitopes of Echinococcus granulosus P14-3-3 &zeta antigen. The nucleotide coding sequence of these epitopes was synthesized by PCR. the ampliqon was digested with XhoI restriction enzyme and cloned into pEGFP–N1 vector That has been purificated by modified sambrook method with CaCl2 and PEG6000..Positive colony was selected by direct colony PCR and confirmed by the sequencing.and evaluation of it's expression in Eukaryotic cells was done by transformed to CHO cell line with electroporation. Results: Linear T-cell epitopes of Echinococcus granulosus P14-3-3 after prediction,synthesis and amplification wae successfully cloned into pEGFP-N1 vector that purificated by new method with maximum vector and minimum RNA concentration.The expression of new constract in CHO cell line as a eukaryotic cells achivment by fluorescent microscope and will be used as a DNA vaccine model to evaluation immuno response in mouse models.   Discussion: Successfully cloning of The linear T-cell epitppes coding sequence of Echinococcus granulosus P14-3-3&zeta antigen into pEGFP-N1 verificated by sequencing and fluorscent microscope images demonstrated expression of recombinant protein in CHO cell line

  16. Methods for modeling chinese hamster ovary (cho) cell metabolism

    DEFF Research Database (Denmark)

    2015-01-01

    Embodiments of the present invention generally relate to the computational analysis and characterization biological networks at the cellular level in Chinese Hamster Ovary (CHO) cells. Based on computational methods utilizing a hamster reference genome, the invention provides methods for identify......Embodiments of the present invention generally relate to the computational analysis and characterization biological networks at the cellular level in Chinese Hamster Ovary (CHO) cells. Based on computational methods utilizing a hamster reference genome, the invention provides methods...

  17. Strategies for adaptation of mAb-producing CHO cells to serum-free medium

    OpenAIRE

    Costa A; Rodrigues M.; Henriques Mariana; Oliveira Rosário; Azeredo Joana

    2011-01-01

    Large-scale production of biopharmaceuticals commonly requires the use of serum-free medium, for safety and cost reasons. However, serum is essential to most mammalian cells growth, and its removal implies a very time-consuming process for cell adaptation. Thus, the aim of the study was to evaluate different strategies for cell adaptation to serum-free medium. Three cell types were used to assess the impact of transfection on adaptation: one common CHO-K1 cell line and two CHO-K1 cells tr...

  18. Rapamycin treatment inhibits CHO cell death in a serum-free suspension culture by autophagy induction.

    Science.gov (United States)

    Lee, Jae Seong; Lee, Gyun Min

    2012-12-01

    Rapamycin, a specific mTOR inhibitor, has been used as a chemical activator in autophagy research both in vitro and in vivo. Recently, autophagy has received attention as an anti-cell death engineering target in addition to apoptosis in the Chinese hamster ovary (CHO) cell engineering field. Here, the effect of rapamycin and the subsequent autophagy induction is investigated on two CHO cell lines, DG44 host and an antibody-producing recombinant CHO (rCHO), in a serum-free suspension culture. In both cell lines, the rapamycin treatment delayed the viability drop and apoptosis induction. In particular, the improved cell viability of the antibody-producing rCHO cell line resulting from the rapamycin treatment led to a 21% increase in the maximum antibody concentration. From observations that a rapamycin derivative, everolimus, demonstrated similar positive effects in both cell lines, but not FK-506, which forms the same complex as rapamycin, but does not inhibit mTOR, it was demonstrated that the positive effects of rapamycin appear to be mTOR-dependent. In addition, the cultivation with rapamycin and/or an autophagy inhibitor, bafilomycin A1, indicated that the autophagy induction is related to the positive effects of rapamycin. The genetic perturbation of the autophagy pathway through the regulation of the expression level of Beclin-1, an important autophagy regulator, resulted in a delayed autophagy induction and apoptosis inhibition in response to the rapamycin treatment in the DG44 host cell line. Taken together, the results obtained in this study imply a positive role for autophagy and predict the usefulness of pro-autophagy engineering in CHO cell cultures.

  19. Importance of Interaction between Integrin and Actin Cytoskeleton in Suspension Adaptation of CHO cells.

    Science.gov (United States)

    Walther, Christa G; Whitfield, Robert; James, David C

    2016-04-01

    The biopharmaceutical production process relies upon mammalian cell technology where single cells proliferate in suspension in a chemically defined synthetic environment. This environment lacks exogenous growth factors, usually contributing to proliferation of fibroblastic cell types such as Chinese hamster ovary (CHO) cells. Use of CHO cells for production hence requires a lengthy 'adaptation' process to select clones capable of proliferation as single cells in suspension. The underlying molecular changes permitting proliferation in suspension are not known. Comparison of the non-suspension-adapted clone CHO-AD and a suspension-adapted propriety cell line CHO-SA by flow cytometric analysis revealed a highly variable bi-modal expression pattern for cell-to-cell contact proteins in contrast to the expression pattern seen for integrins. Those have a uni-modal expression on suspension and adherent cells. Integrins showed a conformation distinguished by regularly distributed clusters forming a sphere on the cell membrane of suspension-adapted cells. Actin cytoskeleton analysis revealed reorganisation from the typical fibrillar morphology found in adherent cells to an enforced spherical subcortical actin sheath in suspension cells. The uni-modal expression and specific clustering of integrins could be confirmed for CHO-S, another suspension cell line. Cytochalasin D treatment resulted in breakdown of the actin sheath and the sphere-like integrin conformation demonstrating the link between integrins and actin in suspension-adapted CHO cells. The data demonstrates the importance of signalling changes, leading to an integrin rearrangement on the cell surface, and the necessity of the reinforcement of the actin cytoskeleton for proliferation in suspension conditions.

  20. Intraclonal protein expression heterogeneity in recombinant CHO cells.

    Directory of Open Access Journals (Sweden)

    Warren Pilbrough

    Full Text Available Therapeutic glycoproteins have played a major role in the commercial success of biotechnology in the post-genomic era. But isolating recombinant mammalian cell lines for large-scale production remains costly and time-consuming, due to substantial variation and unpredictable stability of expression amongst transfected cells, requiring extensive clone screening to identify suitable high producers. Streamlining this process is of considerable interest to industry yet the underlying phenomena are still not well understood. Here we examine an antibody-expressing Chinese hamster ovary (CHO clone at single-cell resolution using flow cytometry and vectors, which couple light and heavy chain transcription to fluorescent markers. Expression variation has traditionally been attributed to genetic heterogeneity arising from random genomic integration of vector DNA. It follows that single cell cloning should yield a homogeneous cell population. We show, in fact, that expression in a clone can be surprisingly heterogeneous (standard deviation 50 to 70% of the mean, approaching the level of variation in mixed transfectant pools, and each antibody chain varies in tandem. Phenotypic variation is fully developed within just 18 days of cloning, yet is not entirely explained by measurement noise, cell size, or the cell cycle. By monitoring the dynamic response of subpopulations and subclones, we show that cells also undergo slow stochastic fluctuations in expression (half-life 2 to 11 generations. Non-genetic diversity may therefore play a greater role in clonal variation than previously thought. This also has unexpected implications for expression stability. Stochastic gene expression noise and selection bias lead to perturbations from steady state at the time of cloning. The resulting transient response as clones reestablish their expression distribution is not ordinarily accounted for but can contribute to declines in median expression over timescales of up to 50

  1. Intraclonal Protein Expression Heterogeneity in Recombinant CHO Cells

    Science.gov (United States)

    Pilbrough, Warren; Munro, Trent P.; Gray, Peter

    2009-01-01

    Therapeutic glycoproteins have played a major role in the commercial success of biotechnology in the post-genomic era. But isolating recombinant mammalian cell lines for large-scale production remains costly and time-consuming, due to substantial variation and unpredictable stability of expression amongst transfected cells, requiring extensive clone screening to identify suitable high producers. Streamlining this process is of considerable interest to industry yet the underlying phenomena are still not well understood. Here we examine an antibody-expressing Chinese hamster ovary (CHO) clone at single-cell resolution using flow cytometry and vectors, which couple light and heavy chain transcription to fluorescent markers. Expression variation has traditionally been attributed to genetic heterogeneity arising from random genomic integration of vector DNA. It follows that single cell cloning should yield a homogeneous cell population. We show, in fact, that expression in a clone can be surprisingly heterogeneous (standard deviation 50 to 70% of the mean), approaching the level of variation in mixed transfectant pools, and each antibody chain varies in tandem. Phenotypic variation is fully developed within just 18 days of cloning, yet is not entirely explained by measurement noise, cell size, or the cell cycle. By monitoring the dynamic response of subpopulations and subclones, we show that cells also undergo slow stochastic fluctuations in expression (half-life 2 to 11 generations). Non-genetic diversity may therefore play a greater role in clonal variation than previously thought. This also has unexpected implications for expression stability. Stochastic gene expression noise and selection bias lead to perturbations from steady state at the time of cloning. The resulting transient response as clones reestablish their expression distribution is not ordinarily accounted for but can contribute to declines in median expression over timescales of up to 50 days. Noise

  2. Identification of a novel temperature sensitive promoter in cho cells

    Directory of Open Access Journals (Sweden)

    Hesse Friedemann

    2011-05-01

    Full Text Available Abstract Background The Chinese hamster ovary (CHO expression system is the leading production platform for manufacturing biopharmaceuticals for the treatment of numerous human diseases. Efforts to optimize the production process also include the genetic construct encoding the therapeutic gene. Here we report about the successful identification of an endogenous highly active gene promoter obtained from CHO cells which shows conditionally inducible gene expression at reduced temperature. Results Based on CHO microarray expression data abundantly transcribed genes were selected as potential promoter candidates. The S100a6 (calcyclin and its flanking regions were identified from a genomic CHO-K1 lambda-phage library. Computational analyses showed a predicted TSS, a TATA-box and several TFBSs within the 1.5 kb region upstream the ATG start signal. Various constructs were investigated for promoter activity at 37°C and 33°C in transient luciferase reporter gene assays. Most constructs showed expression levels even higher than the SV40 control and on average a more than two-fold increase at lower temperature. We identified the core promoter sequence (222 bp comprising two SP1 sites and could show a further increase in activity by duplication of this minimal sequence. Conclusions This novel CHO promoter permits conditionally high-level gene expression. Upon a shift to 33°C, a two to three-fold increase of basal productivity (already higher than SV40 promoter is achieved. This property is of particular advantage for a process with reduced expression during initial cell growth followed by the production phase at low temperature with a boost in expression. Additionally, production of toxic proteins becomes feasible, since cell metabolism and gene expression do not directly interfere. The CHO S100a6 promoter can be characterized as cold-shock responsive with the potential for improving process performance of mammalian expression systems.

  3. Controllability analysis of protein glycosylation in CHO cells.

    Directory of Open Access Journals (Sweden)

    Melissa M St Amand

    Full Text Available To function as intended in vivo, a majority of biopharmaceuticals require specific glycan distributions. However, achieving a precise glycan distribution during manufacturing can be challenging because glycosylation is a non-template driven cellular process, with the potential for significant uncontrolled variability in glycan distributions. As important as the glycan distribution is to the end-use performance of biopharmaceuticals, to date, no strategy exists for controlling glycosylation on-line. However, before expending the significant amount of effort and expense required to develop and implement on-line control strategies to address the problem of glycosylation heterogeneity, it is imperative to assess first the extent to which the very complex process of glycosylation is controllable, thereby establishing what is theoretically achievable prior to any experimental attempts. In this work, we present a novel methodology for assessing the output controllability of glycosylation, a prototypical example of an extremely high-dimensional and very non-linear system. We first discuss a method for obtaining the process gain matrix for glycosylation that involves performing model simulations and data analysis systematically and judiciously according to a statistical design of experiments (DOE scheme and then employing Analysis of Variance (ANOVA to determine the elements of process gain matrix from the resulting simulation data. We then discuss how to use the resulting high-dimensional gain matrix to assess controllability. The utility of this method is demonstrated with a practical example where we assess the controllability of various classes of glycans and of specific glycoforms that are typically found in recombinant biologics produced with Chinese Hamster Ovary (CHO cells. In addition to providing useful insight into the extent to which on-line glycosylation control is achievable in actual manufacturing processes, the results also have important

  4. Controllability analysis of protein glycosylation in CHO cells.

    Science.gov (United States)

    St Amand, Melissa M; Tran, Kevin; Radhakrishnan, Devesh; Robinson, Anne S; Ogunnaike, Babatunde A

    2014-01-01

    To function as intended in vivo, a majority of biopharmaceuticals require specific glycan distributions. However, achieving a precise glycan distribution during manufacturing can be challenging because glycosylation is a non-template driven cellular process, with the potential for significant uncontrolled variability in glycan distributions. As important as the glycan distribution is to the end-use performance of biopharmaceuticals, to date, no strategy exists for controlling glycosylation on-line. However, before expending the significant amount of effort and expense required to develop and implement on-line control strategies to address the problem of glycosylation heterogeneity, it is imperative to assess first the extent to which the very complex process of glycosylation is controllable, thereby establishing what is theoretically achievable prior to any experimental attempts. In this work, we present a novel methodology for assessing the output controllability of glycosylation, a prototypical example of an extremely high-dimensional and very non-linear system. We first discuss a method for obtaining the process gain matrix for glycosylation that involves performing model simulations and data analysis systematically and judiciously according to a statistical design of experiments (DOE) scheme and then employing Analysis of Variance (ANOVA) to determine the elements of process gain matrix from the resulting simulation data. We then discuss how to use the resulting high-dimensional gain matrix to assess controllability. The utility of this method is demonstrated with a practical example where we assess the controllability of various classes of glycans and of specific glycoforms that are typically found in recombinant biologics produced with Chinese Hamster Ovary (CHO) cells. In addition to providing useful insight into the extent to which on-line glycosylation control is achievable in actual manufacturing processes, the results also have important implications for

  5. Engineered CHO cells for production of diverse, homogeneous glycoproteins

    DEFF Research Database (Denmark)

    Yang, Zhang; Wang, Shengjun; Halim, Adnan;

    2015-01-01

    genes controlling N-glycosylation in CHO cells and constructed a design matrix that facilitates the generation of desired glycosylation, such as human-like alpha 2,6-linked sialic acid capping. This engineering approach will aid the production of glycoproteins with improved properties and therapeutic...

  6. Effects of nanosecond pulsed electrical fields (nsPEFs) on the cell cycle of CHO and Jurkat cells

    Science.gov (United States)

    Mahlke, Megan A.; Navara, Christopher; Ibey, Bennett L.

    2014-03-01

    Exposure to nano-second pulsed electrical fields (nsPEFs) can cause poration of external and internal cell membranes, DNA damage, and disassociation of cytoskeletal components, all of which are capable of disrupting a cell's ability to replicate. Variations between cell lines in membrane and cytoskeletal structure as well as in survival of nsPEF exposure should correspond to unique line-dependent cell cycle effects. Additionally, phase of cell cycle during exposure may be linked to differential sensitivities to nsPEFs across cell lines, as DNA structure, membrane elasticity, and cytoskeletal structure change dramatically during the cell cycle. Populations of Jurkat and Chinese Hamster Ovary (CHO) cells were examined post-exposure (10 ns pulse trains at 150kV/cm) by analysis of DNA content via propidium iodide staining and flow cytometric analysis at various time points (1, 6, and 12h post-exposure) to determine population distribution in cell cycle phases. Additionally, CHO and Jurkat cells were synchronized in G1/S and G2/M phases, pulsed, and analyzed to evaluate role of cell cycle phase in survival of nsPEFs. CHO populations recovered similarly to sham populations postnsPEF exposure and did not exhibit a phase-specific change in response. Jurkat cells exhibited considerable apoptosis/necrosis in response to nsPEF exposure and were unable to recover and proliferate in a manner similar to sham exposed cells. Additionally, Jurkat cells appear to be more sensitive to nsPEFs in G2/M phases than in G1/S phases. Recovery of CHO populations suggests that nsPEFs do not inhibit proliferation in CHO cells; however, inhibition of Jurkat cells post-nsPEF exposure coupled with preferential cell death in G2/M phases suggest that cell cycle phase during exposure may be an important factor in determining nsPEF toxicity in certain cell lines. Interestingly, CHO cells have a more robust and rigid cytoskeleton than Jurkat cells which is thought to contribute to their ability to

  7. Recombinant human albumin supports single cell cloning of CHO cells in chemically defined media.

    Science.gov (United States)

    Zhu, Jiang; Wooh, Jong Wei; Hou, Jeff Jia Cheng; Hughes, Benjamin S; Gray, Peter P; Munro, Trent P

    2012-01-01

    Biologic drugs, such as monoclonal antibodies, are commonly made using mammalian cells in culture. The cell lines used for manufacturing should ideally be clonal, meaning derived from a single cell, which represents a technically challenging process. Fetal bovine serum is often used to support low cell density cultures, however, from a regulatory perspective, it is preferable to avoid animal-derived components to increase process consistency and reduce the risk of contamination from adventitious agents. Chinese hamster ovary (CHO) cells are the most widely used cell line in industry and a large number of serum-free, protein-free, and fully chemically defined growth media are commercially available, although these media alone do not readily support efficient single cell cloning. In this work, we have developed a simple, fully defined, single-cell cloning media, specifically for CHO cells, using commercially available reagents. Our results show that a 1:1 mixture of CD-CHO™ and DMEM/F12 supplemented with 1.5 g/L of recombinant albumin (Albucult®) supports single cell cloning. This formulation can support recovery of single cells in 43% of cultures compared to 62% in the presence of serum.

  8. Fucan effect on CHO cell proliferation and migration.

    Science.gov (United States)

    Nobre, Leonardo Thiago Duarte Barreto; Vidal, Arthur Anthunes Jacome; Almeida-Lima, Jailma; Oliveira, Ruth Medeiros; Paredes-Gamero, Edgar Jean; Medeiros, Valquiria Pereira; Trindade, Edvaldo Silva; Franco, Celia Regina Cavichiolo; Nader, Helena Bonciani; Rocha, Hugo Alexandre Oliveira

    2013-10-15

    Fucan is a term used to denominate sulfated L-fucose rich polysaccharides. Here, a heterofucan, named fucan B, was extracted from the Spatoglossum schröederi seaweed. This 21.5 kDa galactofucan inhibited CHO-K1 proliferation and migration when fibronectin was the substrate. Fucan B derivatives revealed that such effects depend on their degree of sulfation. Fucan B did not induce cell death, but promoted G1 cell cycle arrest. Western blotting and flow cytometry analysis suggest that fucan B binds to fibronectin and activates integrin, mainly integrin α5β1, which induces FAK/RAS/MEK/ERK activation. FAK activation inhibits CHO-K1 migration on fibronectin and ERK blocks cell cycle progression. This study indicates that fucan B could be applied in developing new antitumor drugs.

  9. MAR characteristic motifs mediate episomal vector in CHO cells.

    Science.gov (United States)

    Lin, Yan; Li, Zhaoxi; Wang, Tianyun; Wang, Xiaoyin; Wang, Li; Dong, Weihua; Jing, Changqin; Yang, Xianjun

    2015-04-01

    An ideal gene therapy vector should enable persistent transgene expression without limitations in safety and reproducibility. Recent researches' insight into the ability of chromosomal matrix attachment regions (MARs) to mediate episomal maintenance of genetic elements allowed the development of a circular episomal vector. Although a MAR-mediated engineered vector has been developed, little is known on which motifs of MAR confer this function during interaction with the host genome. Here, we report an artificially synthesized DNA fragment containing only characteristic motif sequences that served as an alternative to human beta-interferon matrix attachment region sequence. The potential of the vector to mediate gene transfer in CHO cells was investigated. The short synthetic MAR motifs were found to mediate episomal vector at a low copy number for many generations without integration into the host genome. Higher transgene expression was maintained for at least 4 months. In addition, MAR was maintained episomally and conferred sustained EGFP expression even in nonselective CHO cells. All the results demonstrated that MAR characteristic sequence-based vector can function as stable episomes in CHO cells, supporting long-term and effective transgene expression.

  10. Elucidation of the CHO Super-Ome (CHO-SO) by Proteoinformatics

    DEFF Research Database (Denmark)

    Kumar, Amit; Baycin-Hizal, Deniz; Wolozny, Daniel;

    2015-01-01

    Chinese hamster ovary (CHO) cells are the preferred host cell line for manufacturing a variety of complex biotherapeutic drugs including monoclonal antibodies. We performed a proteomics and bioinformatics analysis on the spent medium from adherent CHO cells. Supernatant from CHO-K1 culture was co...

  11. Deep sequencing reveals different compositions of mRNA transcribed from the F8 gene in a panel of FVIII-producing CHO cell lines

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder; Bolt, Gert; Hansen, Jens J;

    2015-01-01

    Coagulation factor VIII (FVIII) is one of the most complex biopharmaceuticals due to the large size, poor protein stability and extensive post-translational modifications. As a consequence, efficient production of FVIII in mammalian cells poses a major challenge, with typical yields two to three ...

  12. Fucan effect on CHO cell proliferation and migration

    OpenAIRE

    Nobre, Leonardo Thiago Duarte Barreto; Vidal, Arthur Anthunes Jacome; Almeida-Lima, Jailma; Oliveira, Ruth Medeiros; Paredes-Gamero, Edgar Jean [UNIFESP; Medeiros, Valquiria Pereira de [UNIFESP; Trindade, Edvaldo da Silva [UNIFESP; Franco,Celia Regina Cavichiolo; Nader, Helena Bonciani; Rocha, Hugo Alexandre Oliveira

    2013-01-01

    Fucan is a term used to denominate sulfated L-fucose rich polysaccharides. Here, a heterofucan, named fucan B, was extracted from the Spatoglossum schroederi seaweed. This 21.5 kDa galactofucan inhibited CHO-Kl proliferation and migration when fibronectin was the substrate. Fucan B derivatives revealed that such effects depend on their degree of sulfation. Fucan B did not induce cell death, but promoted G1 cell cycle arrest. Western blotting and flow cytometry analysis suggest that fucan B bi...

  13. Endocytosis of a functionally enhanced GFP-tagged transferrin receptor in CHO cells.

    Directory of Open Access Journals (Sweden)

    Qi He

    Full Text Available The endocytosis of transferrin receptor (TfR has served as a model to study the receptor-targeted cargo delivery system for cancer therapy for many years. To accurately evaluate and optically measure this TfR targeting delivery in vitro, a CHO cell line with enhanced green fluorescent protein (EGFP-tagged human TfR was established. A chimera of the hTfR and EGFP was engineered by fusing EGFP to the amino terminus of hTfR. Data were provided to demonstrate that hTfR-EGFP chimera was predominantly localized on the plasma membrane with some intracellular fluorescent structures on CHO cells and the EGFP moiety did not affect the endocytosis property of hTfR. Receptor internalization occurred similarly to that of HepG2 cells expressing wild-type hTfR. The internalization percentage of this chimeric receptor was about 81 ± 3% of wild type. Time-dependent co-localization of hTfR-EGFP and PE-conjugated anti-hTfR mAb in living cells demonstrated the trafficking of mAb-receptor complexes through the endosomes followed by segregation of part of the mAb and receptor at the late stages of endocytosis. The CHO-hTfR cells preferentially took up anti-hTfR mAb conjugated nanoparticles. This CHO-hTfR cell line makes it feasible for accurate evaluation and visualization of intracellular trafficking of therapeutic agents conjugated with transferrin or Abs targeting the hTfRs.

  14. 稳定表达人CCR5基因CHO细胞系的建立及鉴定%Establishment and characterization of CHO cell line stably expressing human CCR5 gene

    Institute of Scientific and Technical Information of China (English)

    程林; 吴喜林; 袁钟平; 吴稚伟

    2012-01-01

    CCR5 is one of the most important co-receptors required for HIV-I infection and a potential target for anti viral agents. In this study,the eukaryotic expression plasmid pcDNA3.1 CCR5 carrying human CCR5 gene was stably transfected into CHO-K1 cells. After 2 weeks selection by G418, cell clones were selected from limited dilution in 96-well plates,and 22 clones were obtained. All the clones were analyzed for cell surface CCR5 expression using flow cytometry, and clone 10 was identified as a high expression clone. The CCR5 gene transcription of the clone 10 was further analyzed using RT PCR and gel electrophoresis,and the target band was visible in the expected location. Cellular ELISA indicated that the surface CCR5 expression of clone 10 was 13. 6 fold higher than the control cells. Our results indicated that the CHO cell line stably expressing human CCR5 can be a useful tool for study viral co receptor,specific antibody screening and anti-viral agents.%CC型趋化因子受体5(CCR5)是HIV-1感染机体所需的最重要的辅助受体和潜在的抗病毒药物靶点之一.将含有人CCR5基因的真核表达质粒pcDNA3.1CCR5稳定转染CHOK1细胞,G418筛选2周后,在96孔板内通过有限稀释法培养细胞单克隆,最后得到22个细胞克隆,用流式细胞术检测细胞表面CCR5蛋白,发现克隆10能够高表达人CCR5基因.使用RT—PCR鉴定克隆10CCR5基因转录情况,结果在预期的位置检测出目的条带.采用细胞ELISA的方法进一步鉴定克隆10细胞表面CCR5的表达,结果该克隆的405nm光密度值是对照组的13.6倍.结果表明,本研究建立的稳定转染人CCR5的CHO细胞系能够高效表达CCR5基因,为研究HIV—1共受体、筛选病毒中和抗体、以及抗病毒药物奠定了基础.

  15. Genetically modified CHO cells for studying the genotoxicity of heterocyclic amines from cooked foods

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.H.; Wu, R.W.; Felton, J.S.

    1995-07-01

    We have developed metabolically competent CHO cells to evaluate the genotoxicity associated with heterocyclic amines, such as those that are present in cooked foods. Into repair-deficient UV5 cells we introduced cDNAs for expressing cytochrome P450IA2 and acetyltransferases. We then genetically reverted these transformed lines to obtain matched metabolically competent repair-deficient/proficient lines. For a high mutagenic response, we find a requirement for acetyltransferase with IQ but not with PhIP. This system allows for both quantifying mutagenesis and analyzing the mutational spectra produced by heterocyclic amines.

  16. Development and validation of a high-content screening in vitro micronucleus assay in CHO-k1 and HepG2 cells

    NARCIS (Netherlands)

    Westerink, W.M.; Schirris, T.J.J.; Horbach, G.J.; Schoonen, W.G.

    2011-01-01

    In the present study an automated image analysis assisted in vitro micronucleus assay was developed with the rodent cell line CHO-k1 and the human hepatoma cell line HepG2, which are both commonly used in regulatory genotoxicity assays. The HepG2 cell line was chosen because of the presence in these

  17. Components of yeast (Sacchromyces cervisiae) extract as defined media additives that support the growth and productivity of CHO cells.

    Science.gov (United States)

    Spearman, Maureen; Chan, Sarah; Jung, Vince; Kowbel, Vanessa; Mendoza, Meg; Miranda, Vivian; Butler, Michael

    2016-09-10

    Yeast and plant hydrolysates are used as media supplements to support the growth and productivity of CHO cultures for biopharmaceutical production. Through fractionation of a yeast lysate and metabolic analysis of a fraction that had bioactivity equivalent to commercial yeast extract (YE), bioactive components were identified that promoted growth and productivity of two recombinant CHO cell lines (CHO-Luc and CHO-hFcEG2) equivalent to or greater than YE-supplemented media. Autolysis of the yeast lysate was not necessary for full activity, suggesting that the active components are present in untreated yeast cells. A bioactive fraction (3KF) of the yeast lysate was isolated from the permeate using a 3kDa molecular weight cut-off (MWCO) filter. Supplementation of this 3KF fraction into the base media supported growth of CHO-Luc cells over eight passages equivalent to YE-supplemented media. The 3KF fraction was fractionated further by a cation exchange spin column using a stepwise pH elution. Metabolomic analysis of a bioactive fraction isolated at high pH identified several arginine and lysine-containing peptides as well as two polyamines, spermine and spermidine, with 3.5× and 4.5× higher levels compared to a fraction showing no bioactivity. The addition of a mixture of polyamines and their precursors (putrescine, spermine, spermidine, ornithine and citrulline) as well as increasing the concentration of some of the components of the original base medium resulted in a chemically-defined (CD) formulation that produced an equivalent viable cell density (VCD) and productivity of the CHO-Luc cells as the YE-supplemented medium. The VCD of the CHO-hFcEG2 culture in the CD medium was 1.9× greater and with equivalent productivity to the YE-supplemented media.

  18. Ubiquitous Chromatin Opening Elements (UCOEs) effect on transgene position and expression stability in CHO cells following methotrexate (MTX) amplification.

    Science.gov (United States)

    Betts, Zeynep; Dickson, Alan J

    2016-03-01

    The requirement for complex therapeutic proteins has resulted in mammalian cells, especially CHO cells, being the dominant host for recombinant protein manufacturing. In creating recombinant CHO cell lines, the expression vectors integrate into various parts of the genome leading to variable levels of expression and stability of protein production. This makes mammalian cell line development a long and laborious process. Therefore, with the intention to accelerate process development of recombinant protein production in CHO systems, UCOEs are utilized to diminish instability of production by maintaining an open chromatin surrounding in combination with MTX amplification. Chromosome painting and FISH analysis were performed to provide detailed molecular evaluation on the location of amplified genes and its relationship to the productivity and stability of the amplified cell lines. In summary, cell lines generated with vectors containing UCOEs retained stable GFP expression with MTX present (but instability was observed in the absence of MTX). UCOE cell lines displayed a higher frequency of integration into >1 chromosome than non-UCOE group. Cell populations were more homogenous in terms of transgene location at the end of Long-term culture (LTC). Overall our findings suggest variation in eGFP fluorescence may be attributed to changes in transgene integration profile over LTC.

  19. Synthesis of human prolactin in Chinese hamster ovary (CHO) cells; Sintese de prolactina humana em celulas de ovario de hamster chines (CHO)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Roberto Jorge

    2000-07-01

    Three different eukaryotic expression vectors, based on the same selectable gene marker (dhfr), have been used for dhf- CHO cells transfection to rapidly isolate stable cell lines capable of secreting high levels of recombinant human prolactin (rec-hPRL). Two vectors, one codifying a human prolactin (p658-hPRL) and the other a tag-prolactin (p658-tagPRL), contain the complete hepatitis B virus-X (HBV-X) gene coding for a viral transactivator and a sequence derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF) that mediates selective dhfr mRNA degradation. These vectors have the advantage of rapidly obtaining stable cell lines without methotrexate amplification. The highest secretion obtained by these vectors was of approximately 10 {mu}g hPRU10{sup 6} cells/day. The other vector (pEDdc-hPRL) is based on a dicistronic expression system, containing an internal ribosome entry site isolated from the encephalomyocarditis (EMC) virus. This vector before amplification provided secretion levels at least 10 fold lower than that obtained with the other two vectors. However, after three steps of methotrexate amplification, it provided some clones able to secrete up to 30 {mu}g hPRU10{sup 6} cells/day. This is the first report describing the production and purification of rec-hPRL from CHO cells, obtaining secretion levels with both vectors higher than those reported so far for this hormone in other eukaryotic systems. CHO-derived rec-hPRL contained approximately 10 % of the glycosylated form, a value that is consistent with results reported for hPRL purified from the pituitary or from transformed murine C-127 cells. CHO-derived rec-hPRL was purified with good yield, obtaining also a good resolution between non-glycosylated and glycosylated prolactin. The latter, when its potency was determined via an in vitro bioassay, presented a 47 % lower bioactivity. A qualitative and quantitative analysis of these forms was also possible thanks to the setting up of a

  20. Comparison of the Production of Recombinant Protein in Suspension Culture of CHO Cells in Spinner Flask and Shake Flask System

    Directory of Open Access Journals (Sweden)

    S.N.Z Zainul Abidin

    2011-12-01

    Full Text Available Chinese hamster ovary (CHO cells have been most widely used as the production host for the commercial production of biopharmaceuticals product. They have been extensively studied and developed, and today provide a stable platform for producing monoclonal antibodies and recombinant proteins. This study was focusing on comparison of suspension culture system by using spinner flask and shake flask for the growth and production of recombinant protein in CHO cell line. The CHO cells were transfected with an expression of DNA plasmid containing lac Z gene which codes for β-galactosidase. The recombinant genes in these CHO cells and the β-galactosidase expressing cells were adapted to suspension culture. The agitation speed for both spinner and shake flask were adjusted accordingly. The experiments were carried out in duplicate and samples were taken for cell count, determination of glucose consumption, lactate production and protein level by using biochemical assay. The result showed that, the cell growth in spinner flask is more favorable then in shake flask. The cell concentration in spinner flask is 58% higher than in shake flask. On the other hand, specific activity of β-galactosidase is 25% higher in spinner flask compared to shake flask, at the same agitation speed.ABSTRAK: Sel ovari hamster China (Chinese hamster ovary (CHO digunakan secara meluas dalam hos pembiakan untuk tujuan komersil produk biofarmaseutikal. Ia telah dikaji dan dibangunkan secara ekstensif, dan kini ia menyediakan landasan yang stabil untuk penghasilan antibodi monoklon dan protein rekombinan. Kajian ini memfokuskan tentang penghasilan protein rekombinan menggunakan kultur ampaian sel CHO di dalam kelalang putar dan kelalang goncang. Sel CHO dimasukkan dengan plasmid DNA yang mengandungi gen lac Z yang juga memberikan kod untuk β-galaktosidase. Sel CHO β-galaktosidase-terungkap dimasukkan ke dalam kultur ampaian. Kelajuan agitasi untuk kedua-dua kelalang putar

  1. Adaptation of CHO cells in serum-free conditions for erythropoietin production: Application of EVOP technique for process optimization.

    Science.gov (United States)

    Jukić, Suzana; Bubenik, Dijana; Pavlović, Nediljko; Tušek, Ana Jurinjak; Srček, Višnja Gaurina

    2016-09-01

    Mammalian cell cultures are the preferred expression systems for the production of biopharmaceuticals requiring posttranslational processing. Usually, cell cultures are cultivated in medium supplemented with serum, which supports cell proliferation, viability, and productivity. However, due to scientific and regulatory concerns, serum-free conditions are required in recombinant protein production. Cell lines that are intended for commercial recombinant protein production have to adapt to serum- or protein-free conditions early in their development. This is a labor- and time-consuming process because of the specific cell requirements related to their adaptation in new microenvironment. In the present study, a Chinese hamster ovary (CHO) cell line producing glycosylated recombinant human erythropoietin (rhEPO) was adapted for growth and rhEPO production in serum- and protein-free conditions. The physiology, growth parameters, and morphology of the CHO cells and rhEPO biosynthesis and structure were closely monitored during the adaptation process to avoid unwanted selection of cell subpopulations. The results showed that the CHO cells were successfully adapted to suspension growth and rhEPO production in the protein-free conditions and that the structure of rhEPO remained nearly unchanged. In addition, during rhEPO production in the protein-free suspension conditions, the agitation rate seem to be significant for optimal process performance in contrast to the initial cell concentration, evaluated through evolutionary operation method.

  2. High-level recombinant protein production in CHO cells using an adenoviral vector and the cumate gene-switch.

    Science.gov (United States)

    Gaillet, Bruno; Gilbert, Rénald; Amziani, Rachid; Guilbault, Claire; Gadoury, Christine; Caron, Antoine W; Mullick, Alaka; Garnier, Alain; Massie, Bernard

    2007-01-01

    To facilitate and accelerate the production of eukaryotic proteins with correct post-translational modifications, we have developed a protein production system based on the transduction of Chinese hamster ovary (CHO) cells using adenovirus vectors (AdVs). We have engineered a CHO cell line (CHO-cTA) that stably expresses the transactivator (cTA) of our newly developed cumate gene-switch transcription system. This cell line is adapted to suspension culture and can grow in serum-free and protein-free medium. To increase the transduction level of AdVs, we have also generated a cell line (CHO-cTA-CAR) that expresses additional amounts of the coxackievirus and adenovirus receptor (CAR) on its surface. Recombinant protein production was tested using an AdV carrying the secreted alkaline phosphatase (SEAP) under the control of the CR5 promoter, which is strongly and specifically activated by binding to cTA. The SEAP expression was linked to the expression of the green fluorescent protein (GFP) through an internal ribosome entry site (IRES) to facilitate titration of the AdV. We monitored SEAP expression on a daily basis for 9 days after transduction of CHO-cTA and CHO-cTA-CAR using different quantities of AdVs at 37 and 30 degrees C. Incubation at the latter temperature increased the production of SEAP at least 10-fold, and the presence of CAR increased the transduction level of the AdV. Maximum SEAP production (63 mg/L) was achieved at 6-7 days post-infection at 30 degrees C by transducing CHO-cTA-CAR with 500 infectious particles/cell. Because numerous AdVs can now be generated within a few weeks and large-scale production of AdVs is now a routine procedure, this system could be used to produce rapidly milligram quantities of a battery of recombinant proteins as well as for large-scale protein production.

  3. Thyroid cell lines in research on goitrogenesis.

    Science.gov (United States)

    Gerber, H; Peter, H J; Asmis, L; Studer, H

    1991-12-01

    Thyroid cell lines have contributed a lot to the understanding of goitrogenesis. The cell lines mostly used in thyroid research are briefly discussed, namely the rat thyroid cell lines FRTL and FRTL-5, the porcine thyroid cell lines PORTHOS and ARTHOS, The sheep thyroid cell lines OVNIS 5H and 6H, the cat thyroid cell lines PETCAT 1 to 4 and ROMCAT, and the human thyroid cell lines FTC-133 and HTh 74. Chinese hamster ovary (CHO) cells and COS-7 cells, stably transfected with TSH receptor cDNA and expressing a functional TSH receptor, are discussed as examples for non-thyroidal cells, transfected with thyroid genes.

  4. A novel regulatory element (E77) isolated from CHO-K1 genomic DNA enhances stable gene expression in Chinese hamster ovary cells.

    Science.gov (United States)

    Kang, Shin-Young; Kim, Yeon-Gu; Kang, Seunghee; Lee, Hong Weon; Lee, Eun Gyo

    2016-05-01

    Vectors flanked by regulatory DNA elements have been used to generate stable cell lines with high productivity and transgene stability; however, regulatory elements in Chinese hamster ovary (CHO) cells, which are the most widely used mammalian cells in biopharmaceutical production, are still poorly understood. We isolated a novel gene regulatory element from CHO-K1 cells, designated E77, which was found to enhance the stable expression of a transgene. A genomic library was constructed by combining CHO-K1 genomic DNA fragments with a CMV promoter-driven GFP expression vector, and the E77 element was isolated by screening. The incorporation of the E77 regulatory element resulted in the generation of an increased number of clones with high expression, thereby enhancing the expression level of the transgene in the stable transfectant cell pool. Interestingly, the E77 element was found to consist of two distinct fragments derived from different locations in the CHO genome shotgun sequence. High and stable transgene expression was obtained in transfected CHO cells by combining these fragments. Additionally, the function of E77 was found to be dependent on its site of insertion and specific orientation in the vector construct. Our findings demonstrate that stable gene expression mediated by the CMV promoter in CHO cells may be improved by the isolated novel gene regulatory element E77 identified in the present study.

  5. Cell density monitoring and control of microencapsulated CHO cell cultures

    OpenAIRE

    Cole, Harriet Emma

    2015-01-01

    Though mammalian cells play a key role in the manufacturing of recombinant glycosylated proteins, cell cultures and productivity are limited by the lack of suitable systems to enable stable perfusion culture. Microencapsulation, or entrapping cells within a semi-permeable membrane, offers the potential to generate high cell density cultures and improve the productivity by mimicking the cells natural environment. However, the cells being secluded by the microcapsules membrane are difficult to ...

  6. Meganuclease-driven targeted integration in CHO-K1 cells for the fast generation of HTS-compatible cell-based assays.

    Science.gov (United States)

    Cabaniols, Jean-Pierre; Ouvry, Christine; Lamamy, Véronique; Fery, Isabelle; Craplet, Marie-Laure; Moulharat, Natacha; Guenin, Sophie-Pénélope; Bedut, Stéphane; Nosjean, Olivier; Ferry, Gilles; Devavry, Séverine; Jacqmarcq, Cécile; Lebuhotel, Céline; Mathis, Luc; Delenda, Christophe; Boutin, Jean A; Duchâteau, Philippe; Cogé, Francis; Pâques, Frédéric

    2010-09-01

    The development of cell-based assays for high-throughput screening (HTS) approaches often requires the generation of stable transformant cell lines. However, these cell lines are essentially created by random integration of a gene of interest (GOI) with no control over the level and stability of gene expression. The authors developed a targeted integration system in Chinese hamster ovary (CHO) cells, called the cellular genome positioning system (cGPS), based on the stimulation of homologous gene targeting by meganucleases. Five different GOIs were knocked in at the same locus in cGPS CHO-K1 cells. Further characterization revealed that the cGPS CHO-K1 system is more rapid (2-week protocol), efficient (all selected clones expressed the GOI), reproducible (GOI expression level variation of 12%), and stable over time (no change in GOI expression after 23 weeks of culture) than classical random integration. Moreover, in all cGPS CHO-K1 targeted clones, the recombinant protein was biologically active and its properties similar to the endogenous protein. This fast and robust method opens the door for creating large collections of cell lines of better quality and expressing therapeutically relevant GOIs at physiological levels, thereby enhancing the potential scope of HTS.

  7. CRISPR/Cas9-mediated genome engineering of CHO cell factories: application and perspectives

    DEFF Research Database (Denmark)

    Lee, Jae Seong; Grav, Lise Marie; Lewis, Nathan E.

    2015-01-01

    repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system enables rapid,easy and efficient engineering of mammalian genomes. It has a wide range of applications frommodification of individual genes to genome-wide screening or regulation of genes. Facile genomeediting using CRISPR/Cas9 empowers...... researchers in the CHO community to elucidate the mechanisticbasis behind high level production of proteins and product quality attributes of interest. Inthis review, we describe the basis of CRISPR/Cas9-mediated genome editing and its applicationfor development of next generation CHO cell factories while...... highlighting both future perspectivesand challenges. As one of the main drivers for the CHO systems biology era, genome engineeringwith CRISPR/Cas9 will pave the way for rational design of CHO cell factories....

  8. N-Glycosylation optimization of recombinant antibodies in CHO cell through process and metabolic engineering

    DEFF Research Database (Denmark)

    Fan, Yuzhou

    Thanks to the recent advances in Chinese hamster ovary (CHO) “omic” revolution, the development of recombinant therapeutic protein bioprocessing using CHO cell factory started to merge with the new biological mindset called systems biology. In order to produce a CHO-derived recombinant therapeutic...... monoclonal antibody (mAb) towards desired patterns, and at the same time try to understand the underlying mechanisms of that from a systems biology perspective. Two different strategies were used and achieved great success in glyco-optimization: 1) optimize media and culture process; 2) Genetically optimize...... part of the thesis, both literature reviews and experimental applications were provided to demonstrate how to use omics data and implement systems biology to understand biological activities, especially N-glycosylation in CHO cells. In the last part of the thesis, the second strategy that apply genetic...

  9. Targeted Gene Deletion Using DNA-Free RNA-Guided Cas9 Nuclease Accelerates Adaptation of CHO Cells to Suspension Culture.

    Science.gov (United States)

    Lee, Namil; Shin, JongOh; Park, Jin Hyoung; Lee, Gyun Min; Cho, Suhyung; Cho, Byung-Kwan

    2016-11-18

    Chinese hamster ovary (CHO) cells are the preferred host for the production of a wide array of biopharmaceuticals. Thus, efficient and rational CHO cell line engineering methods have been in high demand to improve quality and productivity. Here, we provide a novel genome engineering platform for increasing desirable phenotypes of CHO cells based upon the integrative protocol of high-throughput RNA sequencing and DNA-free RNA-guided Cas9 (CRISPR associated protein9) nuclease-based genome editing. For commercial production of therapeutic proteins, CHO cells have been adapted for suspension culture in serum-free media, which is highly beneficial with respect to productivity and economics. To engineer CHO cells for rapid adaptation to a suspension culture, we exploited strand-specific RNA-seq to identify genes differentially expressed according to their adaptation trajectory in serum-free media. More than 180 million sequencing reads were generated and mapped to the currently available 109,152 scaffolds of the CHO-K1 genome. We identified significantly downregulated genes according to the adaptation trajectory and then verified their effects using the genome editing method. Growth-based screening and targeted amplicon sequencing revealed that the functional deletions of Igfbp4 and AqpI gene accelerate suspension adaptation of CHO-K1 cells. The availability of this strand-specific transcriptome sequencing and DNA-free RNA-guided Cas9 nuclease mediated genome editing facilitates the rational design of the CHO cell genome for efficient production of high quality therapeutic proteins.

  10. Enhancement of Human Prolactin Synthesis by Sodium Butyrate Addition to Serum-Free CHO Cell Culture

    Directory of Open Access Journals (Sweden)

    Herbert Rodrigues Goulart

    2010-01-01

    Full Text Available Sodium butyrate (NaBu has been used as a productivity enhancer for the synthesis of recombinant proteins in Chinese hamster ovary (CHO cells. Thus, the influence of NaBu on the production of recombinant human prolactin (hPRL from CHO cells was investigated for the first time. CHO cell cultures were submitted to a treatment with different concentrations of NaBu (0.25 to 4 mM. Quantitative and qualitative analyses by reverse-phase high-performance liquid chromatography (RP-HPLC and Western blot or SDS-PAGE, carried out directly on CHO-conditioned medium, showed that the highest hPRL expression was obtained with 1 mM NaBu. In vitro biological assays based on noble rat lymphoma (Nb2 and mouse pro-B lymphoma (Ba/F3-LLP cells were carried out on purified hPRL. Its bioactivity in the presence of NaBu was not apparently different from that of the First International Reference Reagent of recombinant hPRL (WHO 97/714. Our results show that NaBu increased the synthesis of recombinant hPRL in CHO cells, apparently without compromising either its structure or function.

  11. Experimental verification for in vitro technique confirmation of bystander effect induced by gamma radiation in CHO-K1 cell line; Verificacao experimental para confirmacao da tecnica in vitro do efeito bystander induzido por radiacao gama na linhagem celular CHO-K1

    Energy Technology Data Exchange (ETDEWEB)

    Viana, P.H.L.; Goes, A.M.; Gomes, D.A., E-mail: pedroleroybio@hotmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento Bioquimica e Imunologia. Lab. de Imunologia Celular e Molecular; Grynberg, S.E., E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-08-15

    The bystander effect refers to biological responses detected in cells not directly irradiated but influenced, somehow, by signals transmitted from neighboring irradiated cells. These biological responses include sister chromatid exchange, mutations, micronucleus formation, chromosomal aberrations, carcinogenesis, apoptosis and necrosis. Although its existence is unquestionable, the mechanisms involved on triggering the bystander effect are not yet completely elucidated. Previous studies have shown that the bystander effect depends on a large variety of parameters including the radiation dose, the dose rate, the type of radiation and type of cells or tissue. This study aims to confirm the technique previously used in the literature in human cell lines for the bystander effect verification. The results suggest that the working conditions adopted by the group show technical efficiency and enables the reproduction of the bystander effect. (author)

  12. Genomic landscapes of Chinese hamster ovary cell lines as revealed by the Cricetulus griseus draft genome

    DEFF Research Database (Denmark)

    Lewis, Nathan E; Liu, Xin; Li, Yuxiang;

    2013-01-01

    Chinese hamster ovary (CHO) cells, first isolated in 1957, are the preferred production host for many therapeutic proteins. Although genetic heterogeneity among CHO cell lines has been well documented, a systematic, nucleotide-resolution characterization of their genotypic differences has been...... stymied by the lack of a unifying genomic resource for CHO cells. Here we report a 2.4-Gb draft genome sequence of a female Chinese hamster, Cricetulus griseus, harboring 24,044 genes. We also resequenced and analyzed the genomes of six CHO cell lines from the CHO-K1, DG44 and CHO-S lineages....... This analysis identified hamster genes missing in different CHO cell lines, and detected >3.7 million single-nucleotide polymorphisms (SNPs), 551,240 indels and 7,063 copy number variations. Many mutations are located in genes with functions relevant to bioprocessing, such as apoptosis. The details...

  13. LDH-C can be differentially expressed during fermentation of CHO cells

    Directory of Open Access Journals (Sweden)

    Szperalski Berthold

    2011-11-01

    Full Text Available Abstract Expression of CHO mRNA was measured with special microarrays from the Consortium for Chinese Hamster Ovary (CHO Cell Genomics led by Prof. Wei-Shou Hu of the University of Minnesota and Prof. Miranda Yap of the Bioprocess Technology Institute of A*STAR, Singapore (http://hugroup.cems.umn.edu/CHO/cho_index.html. Cultivation experiments were performed in small scale 2L stirred tank bioreactors. During fermentation a temperature shift of -3°C was performed. This was accompanied by a reduction of the cell specific lactate production rate. The analysis of transcriptome samples before and after the temperature shift with microarrays showed several changes in the expression of available gene markers. LDH-C expression raised about 2 fold after temperature shift. LDH-A did not change. As LDH-C is known to be a specialized isoenzyme in sperm cells for consuming lactate in a lactate containing milieu, LDH-C could be proposed as a target for genetic engineering, facilitating lactate consumption in the late phase of high cell density cultures and prolonging longevity of CHO production cultures by reducing lactate and base accumulation.

  14. miRNA profiling of high, low and non-producing CHO cells during biphasic fed-batch cultivation reveals process relevant targets for host cell engineering.

    Science.gov (United States)

    Stiefel, Fabian; Fischer, Simon; Sczyrba, Alexander; Otte, Kerstin; Hesse, Friedemann

    2016-05-10

    Fed-batch cultivation of recombinant Chinese hamster ovary (CHO) cell lines is one of the most widely used production modes for commercial manufacturing of recombinant protein therapeutics. Furthermore, fed-batch cultivations are often conducted as biphasic processes where the culture temperature is decreased to maximize volumetric product yields. However, it remains to be elucidated which intracellular regulatory elements actually control the observed pro-productive phenotypes. Recently, several studies have revealed microRNAs (miRNAs) to be important molecular switches of cell phenotypes. In this study, we analyzed miRNA profiles of two different recombinant CHO cell lines (high and low producer), and compared them to a non-producing CHO DG44 host cell line during fed-batch cultivation at 37°C versus a temperature shift to 30°C. Taking advantage of next-generation sequencing combined with cluster, correlation and differential expression analyses, we could identify 89 different miRNAs, which were differentially expressed in the different cell lines and cultivation phases. Functional validation experiments using 19 validated target miRNAs confirmed that these miRNAs indeed induced changes in process relevant phenotypes. Furthermore, computational miRNA target prediction combined with functional clustering identified putative target genes and cellular pathways, which might be regulated by these miRNAs. This study systematically identified novel target miRNAs during different phases and conditions of a biphasic fed-batch production process and functionally evaluated their potential for host cell engineering.

  15. A physiological threshold for protection against menadione toxicity by human NAD(P)H : quinone oxidoreductase (NQO1) in Chinese hamster ovary (CHO) cells

    NARCIS (Netherlands)

    Haan, de L.H.J.; Boerboom, A.M.J.F.; Rietjens, I.M.C.M.; Capelle, van D.; Ruijter, de A.J.M.; Jaiswal, A.K.; Aarts, J.M.M.J.G.

    2002-01-01

    NAD(P)H:quinone oxidoreductase 1 (NQO1) has often been suggested to be involved in cancer prevention by means of detoxification of electrophilic quinones. In the present study, a series of Chinese hamster ovary (CHO) cell lines expressing various elevated levels of human NQO1 were generated by stabl

  16. Heterologous Expression of Rat Testis GABAA Receptor β3t Splicing Variant in CHO Cells

    Institute of Scientific and Technical Information of China (English)

    Shi-feng LI; Yu-guang CHEN; Yuan-chang YAN; Yi-ping LI

    2004-01-01

    Objective To characterize a possible retention function of unique sequence in the 5'end of rat testis GABAA receptor β3t splicing variantMethods Rat testis GABAA receptor β3t splicing variant cDNA was cloned and two eukaryotic expression recombinant plasmids of pEGFP-N1 and pEGFP-C1 were constructed respectively by fusing green fluorescent protein to the N or C-terminus of β3t isoform. The recombinant plasmids were transfected into CHO cells by calcium phosphate co-precipitation method. Fluorescence microscope and laser confocal microscope were used to analyze localization of β3t in the transfected cells. ConA-Texas-Red was used to label cell ER and the localization of rat testis β3t splicing variant in CHO cells was determined.Results When rat testis β3t splicing variant was expressed in CHO cells, two expression patterns were delineated, the distributions of uniform and mainly discrete intracellular compartments respectively. The chimera product failed to be translocated into the cell surface when expressed in CHO cells; whereas the β3 subunit of rat brain was incorporated into the plasma membrane.Conclusion The inability of β3t to target into the ER may be a consequence of the unique 25 specific amino acid segments in the N terminus.

  17. Genomic landscapes of Chinese hamster ovary cell lines as revealed by the Cricetulus griseus draft genome

    DEFF Research Database (Denmark)

    Lewis, Nathan E; Liu, Xin; Li, Yuxiang;

    2013-01-01

    Chinese hamster ovary (CHO) cells, first isolated in 1957, are the preferred production host for many therapeutic proteins. Although genetic heterogeneity among CHO cell lines has been well documented, a systematic, nucleotide-resolution characterization of their genotypic differences has been st...... of this genetic diversity highlight the value of the hamster genome as the reference upon which CHO cells can be studied and engineered for protein production....... stymied by the lack of a unifying genomic resource for CHO cells. Here we report a 2.4-Gb draft genome sequence of a female Chinese hamster, Cricetulus griseus, harboring 24,044 genes. We also resequenced and analyzed the genomes of six CHO cell lines from the CHO-K1, DG44 and CHO-S lineages...

  18. Enhanced sialylation of recombinant erythropoietin in CHO cells by human glycosyltransferase expression.

    Science.gov (United States)

    Jeong, Yeon Tae; Choi, One; Lim, Hye Rim; Son, Young Dok; Kim, Hong Jin; Kim, Jung Hoe

    2008-12-01

    Sialylation, the attachment of sialic acid residues to a protein, can affect the biological activity and in vivo circulatory half-life of glycoproteins. Human alpha2,3- sialyltransferase (alpha2,3-ST) and beta1,4-galactosyltransferase (beta1,4-GT) are responsible for terminal sialylation and galactosylation, respectively. Enhanced sialylation of human erythropoietin (EPO) by the expression of alpha2,3-ST and beta1,4-GT was achieved using recombinant Chinese hamster ovary (CHO) cells (EC1). The sialic acid content and sialylation of N-glycans were evaluated by HPLC. When alpha2,3-ST was expressed in CHO cells (EC1-ST2), the sialic acid content (moles of sialic acid/mole of EPO) increased from 6.7 to 7.5. In addition, the amount of trisialylated glycans increased from 17.3% to 26.1%. When alpha2,3-ST and beta1,4-GT were coexpressed in CHO cells (EC1-GTST15), the degree of sialylation was greater than that in EC1-ST2 cells. In the case of EC1-GTST15 cells, the sialic acid content increased to 8.2 and the proportion of trisialylated glycans was markedly increased from 17.3% to 35.5%. Interestingly, the amount of asialoglycans decreased only in the case of GTST15 cells (21.4% to 14.2%). These results show that coexpression of alpha2,3- ST and beta1,4-GT is more effective than the expression of alpha2,3-ST alone. Coexpression of alpha2,3-ST and beta1,4-GT did not affect CHO cell growth and metabolism or EPO production. Thus, coexpression of alpha2,3-ST and beta1,4-GT may be beneficial for producing therapeutic glycoproteins with enhanced sialylation in CHO cells.

  19. Intracellular CHO cell metabolite profiling reveals steady-state dependent metabolic fingerprints in perfusion culture.

    Science.gov (United States)

    Karst, Daniel J; Steinhoff, Robert; Kopp, Marie R G; Serra, Elisa; Soos, Miroslav; Zenobi, Renato; Morbidelli, Massimo

    2016-12-20

    Perfusion cell culture processes allow the steady-state culture of mammalian cells at high viable cell density, which is beneficial for overall product yields and homogeneity of product quality in the manufacturing of therapeutic proteins. In this study, the extent of metabolic steady state and the change of the metabolite profile between different steady states of an industrial Chinese hamster ovary (CHO) cell line producing a monoclonal antibody (mAb) was investigated in stirred tank perfusion bioreactors. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) of daily cell extracts revealed more than a hundred peaks, among which 76 metabolites were identified by tandem MS (MS/MS) and high resolution Fourier transform ion cyclotron resonance (FT-ICR) MS. Nucleotide ratios (Uridine (U)-ratio, Nucleotide triphosphate (NTP)-ratio and energy charge (EC)) and multivariate analysis of all features indicated a consistent metabolite profile for a stable culture performed at 40 × 10(6) cells/mL over 26 days of culture. On the other hand the reactor was operated continuously so as to reach three distinct steady states one after the other at 20, 60 and 40 × 10(6) cells/mL. In each case, a stable metabolite profile was achieved after an initial transient phase of approximately three days at constant cell density when varying between these set points. Clear clustering according to cell density was observed by principal component analysis, indicating steady state dependent metabolite profiles. In particular, varying levels of nucleotides, nucleotide sugar and lipid precursors explained most of the variance between the different cell density set points. This article is protected by copyright. All rights reserved.

  20. Site-specific integration in CHO cells mediated by CRISPR/Cas9 and homology-directed DNA repair pathway

    DEFF Research Database (Denmark)

    Lee, Jae Seong; Beuchert Kallehauge, Thomas; Pedersen, Lasse Ebdrup

    2015-01-01

    gene integration into site-specific loci in CHO cells using CRISPR/Cas9 genome editing system and compatible donor plasmid harboring a gene of interest (GOI) and short homology arms. This strategy has enabled precise insertion of a 3.7-kb gene expression cassette at defined loci in CHO cells following...

  1. In situ monitoring of intracellular glucose and glutamine in CHO cell culture.

    Directory of Open Access Journals (Sweden)

    Alireza Behjousiar

    Full Text Available The development of processes to produce biopharmaceuticals industrially is still largely empirical and relies on optimizing both medium formulation and cell line in a product-specific manner. Current small-scale (well plate-based process development methods cannot provide sufficient sample volume for analysis, to obtain information on nutrient utilization which can be problematic when processes are scaled to industrial fermenters. We envision a platform where essential metabolites can be monitored non-invasively and in real time in an ultra-low volume assay in order to provide additional information on cellular metabolism in high throughput screens. Towards this end, we have developed a model system of Chinese Hamster Ovary cells stably expressing protein-based biosensors for glucose and glutamine. Herein, we demonstrate that these can accurately reflect changing intracellular metabolite concentrations in vivo during batch and fed-batch culture of CHO cells. The ability to monitor intracellular depletion of essential nutrients in high throughput will allow rapid development of improved bioprocesses.

  2. BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; YU Yaoting; PAN Jilun; XU Yuanping; ZHU Hesun

    2001-01-01

    The surface of polypropylene (PP) membrane was modified by low temperature plasma with ammonia. The effect of exposure time was investigated by means of contact angle measurement. The results show that low temperature ammonia plcsma treatment can enhance its hydrophilicity. Chinese hamster ovary (CHO) cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.

  3. CHO Quasispecies—Implications for Manufacturing Processes

    Directory of Open Access Journals (Sweden)

    Florian M. Wurm

    2013-10-01

    Full Text Available Chinese hamster ovary (CHO cells are a source of multi-ton quantities of protein pharmaceuticals. They are, however, immortalized cells, characterized by a high degree of genetic and phenotypic diversity. As is known for any biological system, this diversity is enhanced by selective forces when laboratories (no sharing of gene pools grow cells under (diverse conditions that are practical and useful. CHO cells have been used in culture for more than 50 years, and various lines of cells are available and have been used in manufacturing. This article tries to represent, in a cursory way, the history of CHO cells, particularly the origin and subsequent fate of key cell lines. It is proposed that the name CHO represents many different cell types, based on their inherent genetic diversity and their dynamic rate of genetic change. The continuing remodeling of genomic structure in clonal or non-clonal cell populations, particularly due to the non-standardized culture conditions in hundreds of different labs renders CHO cells a typical case for “quasispecies”. This term was coined for families of related (genomic sequences exposed to high mutation rate environments where a large fraction of offspring is expected to carry one or more mutations. The implications of the quasispecies concept for CHO cells used in protein manufacturing processes are significant. CHO genomics/transcriptomics may provide only limited insights when done on one or two “old” and poorly characterized CHO strains. In contrast, screening of clonal cell lines, derived from a well-defined starting material, possibly within a given academic or industrial environment, may reveal a more narrow diversity of phenotypes with respect to physiological/metabolic activities and, thus, allow more precise and reliable predictions of the potential of a clone for high-yielding manufacturing processes.

  4. Receptor-mediated stimulation of lipid signalling pathways in CHO cells elicits the rapid transient induction of the PDE1B isoform of Ca2+/calmodulin-stimulated cAMP phosphodiesterase.

    Science.gov (United States)

    Spence, S; Rena, G; Sullivan, M; Erdogan, S; Houslay, M D

    1997-01-01

    Chinese hamster ovary cells (CHO cells) do not exhibit any Ca2+/calmodulin-stimulated cAMP phosphodiesterase (PDE1) activity. Challenge of CHO cells with agonists for endogenous P2-purinoceptors, lysophosphatidic acid receptors and thrombin receptors caused a similar rapid transient induction of PDE1 activity in each instance. This was also evident on noradrenaline challenge of a cloned CHO cell line transfected so as to overexpress alpha 1B-adrenoceptors. This novel PDE1 activity appeared within about 15 min of exposure to ligands, rose to a maximum value within 30 min to 1 h and then rapidly decreased. In each case, the expression of novel PDE1 activity was blocked by the transcriptional inhibitor actinomycin D. Challenge with insulin of either native CHO cells or a CHO cell line transfected so as to overexpress the human insulin receptor failed to induce PDE1 activity. Reverse transcriptase-PCR analyses, using degenerate primers able to detect the PDE1C isoform, did not amplify any fragment from RNA preparations of CHO cells expressing PDE1 activity, although they did so from the human thyroid carcinoma FTC133 cell line. Reverse transcriptase-PCR analyses, using degenerate primers able to detect the PDE1A and PDE1B isoforms, successfully amplified a fragment of the predicted size from RNA preparations of both CHO cells expressing PDE1 activity and human Jurkat T-cells. Sequencing of the PCR products, generated using the PDE1A/B primers, yielded a novel sequence which, by analogy with sequences reported for bovine and murine PDE1B forms, suggests that the PDE1 species induced in CHO cells through protein kinase C activation and that expressed in Jurkat T-cells are PDE1B forms.

  5. Carboxypeptidase D is the only enzyme responsible for antibody C-terminal lysine cleavage in Chinese hamster ovary (CHO) cells.

    Science.gov (United States)

    Hu, Zhilan; Zhang, Henry; Haley, Benjamin; Macchi, Frank; Yang, Feng; Misaghi, Shahram; Elich, Joseph; Yang, Renee; Tang, Yun; Joly, John C; Snedecor, Bradley R; Shen, Amy

    2016-10-01

    Heterogeneity of C-terminal lysine levels often observed in therapeutic monoclonal antibodies is believed to result from the proteolysis by endogenous carboxypeptidase(s) during cell culture production. Identifying the responsible carboxypeptidase(s) for C-terminal lysine cleavage in CHO cells would provide valuable insights for antibody production cell culture processes development and optimization. In this study, five carboxypeptidases, CpD, CpM, CpN, CpB, and CpE, were studied for message RNA (mRNA) expression by qRT-PCR analysis in two most commonly used blank hosts (DUXB-11 derived DHFR-deficient DP12 host and DHFR-positive CHOK1 host), used for therapeutic antibody production, as well an antibody-expressing cell line derived from each host. Our results showed that CpD had the highest mRNA expression. When CpD mRNA levels were reduced by RNAi (RNA interference) technology, C-terminal lysine levels increased, whereas there was no obvious change in C-terminal lysine levels when a different carboxypeptidase mRNA level was knocked down suggesting that carboxypeptidase D is the main contributor for C-terminal lysine processing. Most importantly, when CpD expression was knocked out by CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology, C-terminal lysine cleavage was completely abolished in CpD knockout cells based on mass spectrometry analysis, demonstrating that CpD is the only endogenous carboxypeptidase that cleaves antibody heavy chain C-terminal lysine in CHO cells. Hence, our work showed for the first time that the cleavage of antibody heavy chain C-terminal lysine is solely mediated by the carboxypeptidase D in CHO cells and our finding provides one solution to eliminating C-terminal lysine heterogeneity for therapeutic antibody production by knocking out CpD gene expression. Biotechnol. Bioeng. 2016;113: 2100-2106. © 2016 Wiley Periodicals, Inc.

  6. Chinese hamster ovary (CHO) host cell engineering to increase sialylation of recombinant therapeutic proteins by modulating sialyltransferase expression.

    Science.gov (United States)

    Lin, Nan; Mascarenhas, Joaquina; Sealover, Natalie R; George, Henry J; Brooks, Jeanne; Kayser, Kevin J; Gau, Brian; Yasa, Isil; Azadi, Parastoo; Archer-Hartmann, Stephanie

    2015-01-01

    N-Glycans of human proteins possess both α2,6- and α2,3-linked terminal sialic acid (SA). Recombinant glycoproteins produced in Chinese hamster overy (CHO) only have α2,3-linkage due to the absence of α2,6-sialyltransferase (St6gal1) expression. The Chinese hamster ST6GAL1 was successfully overexpressed using a plasmid expression vector in three recombinant immunoglobulin G (IgG)-producing CHO cell lines. The stably transfected cell lines were enriched for ST6GAL1 overexpression using FITC-Sambucus nigra (SNA) lectin that preferentially binds α2,6-linked SA. The presence of α2,6-linked SA was confirmed using a novel LTQ Linear Ion Trap Mass Spectrometry (LTQ MS) method including MSn fragmentation in the enriched ST6GAL1 Clone 27. Furthermore, the total SA (mol/mol) in IgG produced by the enriched ST6GAL1 Clone 27 increased by 2-fold compared to the control. For host cell engineering, the CHOZN(®) GS host cell line was transfected and enriched for ST6GAL1 overexpression. Single-cell clones were derived from the enriched population and selected based on FITC-SNA staining and St6gal1 expression. Two clones ("ST6GAL1 OE Clone 31 and 32") were confirmed for the presence of α2,6-linked SA in total host cell protein extracts. ST6GAL1 OE Clone 32 was subsequently used to express SAFC human IgG1. The recombinant IgG expressed in this host cell line was confirmed to have α2,6-linked SA and increased total SA content. In conclusion, overexpression of St6gal1 is sufficient to produce recombinant proteins with increased sialylation and more human-like glycoprofiles without combinatorial engineering of other sialylation pathway genes. This work represents our ongoing effort of glycoengineering in CHO host cell lines for the development of "bio-better" protein therapeutics and cell culture vaccine production.

  7. [Expression of human IL-35-IgG4 (Fc) fusion protein in CHO/DG44 cells].

    Science.gov (United States)

    Tang, Jing; Gao, Wenda; Zhang, Qing; Zhang, Dawei; Chen, Yang; He, Bo; Liu, Quansheng

    2009-01-01

    We constructed the eukaryotic expression vector of human IL-35-IgG4 (Fc)-pOptiVEC-TOPO by gene recombination technique and expressed the fusion protein human IL-35-IgG4 (Fc) in CHO/DG44 cells. The two components of the newly discovered cytokine human IL-35, EBI3 and IL-12p35, were amplified by PCR from the cDNA library derived from the KG-I cells after LPS induction. The two PCR-amplified cDNA fragments of human IL-35 were linked by over-lapping PCR and then cloned into the IgG4 (Fc)-pOptiVEC-TOPO vector. The constructed plasmid with the recombinant cDNA IL-35-IgG4 (Fc) was verified by restriction enzyme digestion analysis, PCR and DNA sequencing. The verified plasmid with the recombinant cDNA was transfected into CHO/DG44 cells using Lipofectamine 2000. The success of the transfection was examined and confirmed by RT-PCR. After selection in alpha-MEM (-) medium, the IL-35-Ig G4 (Fc) positive CHO/DG44 clones were chosen and the media from these positive clones were collected to be used to purify the fusion protein. The positive CHO/DG44 clones were further cultured in increasing concentrations of MTX and the expression levels of the fusion protein IL-35-Ig G4 (Fc) were repetitively induced by MTX-induced gene amplification. The IL-35-IgG4 (Fc) fusion protein was purified from the media collected from the positive CHO/DG44 clones by protein G affinity chromatography and then identified by SDS-PAGE and Western blotting. The results showed that one protein band was found to match well with the predicted relative molecular mass of human IL-35-IgG4 (Fc) and this protein could specifically bind to anti-human IgG4 (Fc) monoclonal antibody. In conclusion, our study successfully established an IL-35-IgG4 (Fc) positive DG44 cell line which could stably express IL-35-IgG4 (Fc) fusion protein.

  8. Modeling shear-induced CHO cell damage in a rotary positive displacement pump.

    Science.gov (United States)

    Kamaraju, Hari; Wetzel, Kenneth; Kelly, William J

    2010-01-01

    Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross-flow filtration. In this research, CHO cells grown in 20-L bioreactors were fed to a rotary lobe pump in both single pass and recycle experiments were conducted at different RPMs and "slip" conditions. The results indicate that the slip flow rate more severely impacts the viability of the CHO cells than the pump RPM. A novel mathematical modeling approach is presented that predicts shear rates in all of the positive displacement pump's slip regions, and then predicts cell death vs. operating conditions. This model accounts for the complex flow situation that results from changes to RPM, backpressure and pump geometry (i.e., clearances).

  9. Optimization of PTS2-EGFP Expression in CHO and Vero Cells

    Directory of Open Access Journals (Sweden)

    Roozbeh Ghodratnama

    2007-01-01

    Full Text Available Objective: Reporter gene transfer to mammalian cells receives a great deal of attention due to its importance for molecular biology, embryology and developmental biology studies. Among DNA transfer technologies to eukaryotic cells, lipofection is known as the most widely used because of its easy handling procedure, low cell mortality and the natural pathway it undertakes.Materials and Methods: In this study we have examined the transfectability of two cell types: CHO and Vero cells via Lipofection in four different treatments, with combination of exposure duration, 3 and 6 hrs, and different plasmid DNA concentration, 0.5 and 1μgs. A fusion protein expression vector, pUcD2. PTS2-EGFP was used to direct the EGFP protein to peroxisomes after expression of related cDNA. An SPSS analysis was preformed after counting the positive cells.Results: optimum gene expression was found when using 1 μg DNA treated for three hrs for CHO cells, and 1 μg DNA treated for six hrs for Vero cells.Conclusion: The result suggests that CHO lipofection efficiency is significantly increased by both the DNA concentration and exposure time increment; however, an increase in exposure time has less significant effect on low DNA concentration conditions. The same results have been observed for Vero cells. Optimum expression was obtained with highest DNA concentration.

  10. In what time scale proton transfer takes place in a live CHO cell?

    Science.gov (United States)

    Mojumdar, Supratik Sen; Chowdhury, Rajdeep; Mandal, Amit Kumar; Bhattacharyya, Kankan

    2013-06-01

    Excited state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6-trisulfonate, HPTS) in a live Chinese hamster ovary (CHO) cell is studied by time resolved confocal microscopy. The cytoplasm region of the cell is stained by a photoacid, HPTS (HA). The time constant of initial proton transfer (τPT) in the cell is found to be ˜10 times longer than that in bulk water, while the time constants of recombination (τrec) and dissociation (τdiss) in the cell are ˜3 times and ˜2 times longer, respectively. The slower rate of proton transfer (˜10 times) inside the CHO cell compared to that in bulk water is ascribed to slower solvation dynamics, lower availability of free water molecules, and disruption of hydrogen-bond network inside the cell. Translational and rotational diffusion of HPTS inside a single CHO cell have been investigated by fluorescence correlation spectroscopy (FCS) and picosecond anisotropy measurement, respectively. Both the translational and rotational diffusion slow down inside the live cell. FCS studies indicate that HPTS remains tightly bound to a macromolecule inside the cell.

  11. Designing media for animal cell culture: CHO cells, the industrial standard.

    Science.gov (United States)

    Landauer, Karlheinz

    2014-01-01

    The success of culturing CHO cells solely depends on functionality of the used media. Cell culture technology is more than 50 years old, and the knowledge of cell requirements increased steadily. In the beginning, animal-sourced components were the key to growth. Nowadays state-of-the-art media do not contain any animal or naturally sourced components. The compositions are based on scientific awareness of the needs of the cells. The result is high lot-to-lot consistency and high performance.In this book section, a method for the development of a synthetic, animal component-free medium is described. The composition is based on public available formulations and information based on the work of many scientists printed in numerous papers and manuscripts. The method shall help beginners to design their own medium, although some knowledge of biochemistry and animal cells is still required.

  12. Very high cell density perfusion of CHO cells anchored in a non-woven matrix-based bioreactor.

    Science.gov (United States)

    Zhang, Ye; Stobbe, Per; Silvander, Christian Orrego; Chotteau, Véronique

    2015-11-10

    Recombinant Chinese Hamster Ovary (CHO) cells producing IgG monoclonal antibody were cultivated in a novel perfusion culture system CellTank, integrating the bioreactor and the cell retention function. In this system, the cells were harbored in a non-woven polyester matrix perfused by the culture medium and immersed in a reservoir. Although adapted to suspension, the CHO cells stayed entrapped in the matrix. The cell-free medium was efficiently circulated from the reservoir into- and through the matrix by a centrifugal pump placed at the bottom of the bioreactor resulting in highly homogenous concentrations of the nutrients and metabolites in the whole system as confirmed by measurements from different sampling locations. A real-time biomass sensor using the dielectric properties of living cells was used to measure the cell density. The performances of the CellTank were studied in three perfusion runs. A very high cell density measured as 200 pF/cm (where 1 pF/cm is equivalent to 1 × 10(6)viable cells/mL) was achieved at a perfusion rate of 10 reactor volumes per day (RV/day) in the first run. In the second run, the effect of cell growth arrest by hypothermia at temperatures lowered gradually from 37 °C to 29 °C was studied during 13 days at cell densities above 100 pF/cm. Finally a production run was performed at high cell densities, where a temperature shift to 31 °C was applied at cell density 100 pF/cm during a production period of 14 days in minimized feeding conditions. The IgG concentrations were comparable in the matrix and in the harvest line in all the runs, indicating no retention of the product of interest. The cell specific productivity was comparable or higher than in Erlenmeyer flask batch culture. During the production run, the final harvested IgG production was 35 times higher in the CellTank compared to a repeated batch culture in the same vessel volume during the same time period.

  13. Reduction of ammonia and lactate through the coupling of glutamine synthetase selection and downregulation of lactate dehydrogenase-A in CHO cells.

    Science.gov (United States)

    Noh, Soo Min; Park, Jin Hyoung; Lim, Myung Sin; Kim, Jong Won; Lee, Gyun Min

    2017-02-01

    Chinese hamster ovary (CHO) cell cultivation for production of therapeutic proteins is accompanied by production of metabolic wastes, mostly ammonia and lactate. To reduce ammonia production, the glutamine synthetase (GS) system was used to develop therapeutic monoclonal antibody (mAb)-producing CHO cells (SM-0.025). Additionally, the lactate dehydrogenase-A (LDH-A) was downregulated with shRNA to reduce lactate production in SM-0.025. The resulting mAb-producing cell lines (#2, #46, and #52) produced less ammonia than the host cell line during the exponential phase due to GS protein overexpression. LDH-A downregulation in SM-0.025 not only reduced lactate production but also further reduced ammonia production. Among the three LDH-A-downregulated clones, clone #2 had the highest mAb production along with significantly reduced specific lactate and ammonia production rates compared to those in SM-0.025. Waste reduction increased the galactosylation level of N-glycosylation, which improved mAb quality. LDH-A downregulation was also successfully applied to the host cell lines (CHO K1 and GS knockout CHO-K1). However, LDH-A downregulated host cells could not survive the pool-selection process wherein glutamine was excluded and methionine sulfoximine was added to the media. Taken together, LDH-A downregulation in the mAb-producing cell line generated with the GS system successfully reduced both ammonia and lactate levels, improving mAb galactosylation. However, LDH-A downregulation could not be applied to host cell lines because it hampered the selection process of the GS system.

  14. Cytotoxicity of acrylamide and its epoxide glycidamide in CHO cells expressing human cytochrome P450 2E1

    Institute of Scientific and Technical Information of China (English)

    Shoulin Wang; Xiaoyang He; Xinru Wang; Junyan Hong

    2006-01-01

    Objective: To investigate whether CYP2E1 is responsible for the acrylamide metabolic activation in Flp-In CHO cell system. Methods: CYP2E1 cDNA was subcloned from the human liver full-length cDNA library and subsequently transfected into the Flp-In CHO cells to generate the stable transfectant of CYP2E1. The CYP2E1 mRNA expression was determined by RT-PCR. Acrylamide and its epoxide glycidamide induced cytotoxicity and cell cycle arrest in G2/M were conducted using MTS assay and flow cytometry, respectively. Results: In the CHO cell stably expressing CYP2E1 (CHO-2E1), a ~1.5 kbsize of band was detected from the mRNA in the cells while no corresponding band in the CHO-vector cells, which indicated that CYP2E1 was successfully transfected in the CHO cells. Compared with the CHO-vector cells, acrylamide showed a concentrationdependent loss of viability in the CHO-2E1 cells but no significant change of G2/M arrest was found. As expected, glycidamide induced similar profile of cytotoxicity in both of the cells, and G2/M arrest presented a concentration-dependent increased in the CHO-2E1 cells. Conclusion: The result suggested that CYP2E1 might be responsible for the acrylamide metabolism, and its metabolite glycidamide was a direct cytotoxic and genotoxic agent. It should be further considered whether acrylamide-induced toxicity is through its epoxide glycidamide in the presence of CYP2E1.

  15. Fed-batch CHO cell culture for lab-scale antibody production

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Ley, Daniel; Andersen, Mikael Rørdam

    2016-01-01

    Fed-batch culture is the most commonly used upstream process in industry today for recombinant monoclonal antibody production using Chinese hamster ovary cells. Developing and optimizing this process in the lab is crucial for establishing process knowledge, which enable rapid and predictable tech......-transfer to manufacturing scale. In this chapter, we will describe stepwise how to carry out fed-batch CHO cell culture for lab-scale antibody production....

  16. Effects of Iron-Oxide Nanoparticle Surface Chemistry on Uptake Kinetics and Cytotoxicity in CHO-K1 Cells

    Directory of Open Access Journals (Sweden)

    Camille C. Hanot

    2015-12-01

    Full Text Available Superparamagnetic iron-oxide nanoparticles (SPIONs show great promise for multiple applications in biomedicine. While a number of studies have examined their safety profile, the toxicity of these particles on reproductive organs remains uncertain. The goal of this study was to evaluate the cytotoxicity of starch-coated, aminated, and PEGylated SPIONs on a cell line derived from Chinese Hamster ovaries (CHO-K1 cells. We evaluated the effect of particle diameter (50 and 100 nm and polyethylene glycol (PEG chain length (2k, 5k and 20k Da on the cytotoxicity of SPIONs by investigating cell viability using the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT and sulforhodamine B (SRB assays. The kinetics and extent of SPION uptake by CHO-K1 cells was also studied, as well as the resulting generation of intracellular reactive oxygen species (ROS. Cell toxicity profiles of SPIONs correlated strongly with their cellular uptake kinetics, which was strongly dependent on surface properties of the particles. PEGylation caused a decrease in both uptake and cytotoxicity compared to aminated SPIONs. Interestingly, 2k Da PEG-modifed SPIONs displayed the lowest cellular uptake and cytotoxicity among all studied particles. These results emphasize the importance of surface coatings when engineering nanoparticles for biomedical applications.

  17. Expression of HNP1cDNA in CHO-dhfr- cells

    Institute of Scientific and Technical Information of China (English)

    LIU Juan; SUN Yong-tao; DU De-wei; WANG Lin-xu; ZHAI Song; WANG Shao-yang; WANG Ding-cheng

    2004-01-01

    To prepare secretary recombinant human neutrophil peptide1 (HNP1)and test its antimicrobialactivity. Methods: The eukaryotic expression vector pcDNA3. 1/V5-His-TOPO-HNP1 was cotransfected with plasmidpDCH1P11 carrying dhfr gene into dhfr- negative CHO (CHO-dhfr-) cells and recombinant protein was verified by ELISA;G418 selective medium was used to screen the stably expressing cell clones followed by serial passages in 5 × 10-8 mol/L and5 × 10-7 mol/L methotrexate (MTX) for gene amplification. Finally 4 cell clones with high expression level were obtainedand confirmed by ELISA, RT-PCR and IFA. The bacteriastatic activity of concentrated supernatants was tested in vitro asthat was almost 200-fold increase than that in G418 selective medium. 303 bp segments were amplified from 4 tably tranfec-tant cloneswhich matched the length of HNP1 cDNA by RT-PCR. Strong fluorescence was visible in cell plasma in the sta-blly transfectant cells by IFA. K-B disc agar diffusion test showed obvious bacteriastatic diffusion on MH plate of E. Coli.Conclusion: HNP1cDNA can be strongly expressed in CHO-dhfr- cells, which supernatants exhibited high inhibitive effectagainst bacteria.

  18. Silver nanoparticle induced cytotoxicity, oxidative stress, and DNA damage in CHO cells

    Science.gov (United States)

    Awasthi, Kumud Kant; Awasthi, Anjali; Kumar, Narender; Roy, Partha; Awasthi, Kamlendra; John, P. J.

    2013-09-01

    Silver nanoparticles (Ag NPs) are being used increasingly in wound dressings, catheters, and in various household products due to their antimicrobial activity. The present study reports the toxicity evaluation of synthesized and well characterized Ag NPs using Chinese hamster ovary (CHO) cells. The UV-Vis spectroscopy reveals the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 408-410 nm. Transmission electron microscopy (TEM) reveals that the average diameter of silver nanoparticles is about 5.0 ± 1.0 nm and that they have spherical shape. Cell visibility and cell viability percentage show dose-dependent cellular toxicity of Ag NPs. The half maximal inhibitory concentration (IC50) for CHO cells is 68.0 ± 2.65 μg/ml after 24 h Ag NPs exposure. Toxicity evaluations, including cellular morphology, mitochondrial function (MTT assay), reactive oxygen species (ROS), and DNA fragmentation assay (Ladder pattern) were assessed in unexposed CHO cells (control) and the cells exposed to Ag NPs concentrations of 15, 30, and 60 μg/ml for 24 h. The findings may assist in the designing of Ag NPs for various applications and provide insights into their toxicity.

  19. Silver nanoparticle induced cytotoxicity, oxidative stress, and DNA damage in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Awasthi, Kumud Kant [University of Rajasthan, Department of Zoology (India); Awasthi, Anjali; Kumar, Narender; Roy, Partha [Indian Institute of Technology Roorkee, Department of Biotechnology (India); Awasthi, Kamlendra, E-mail: kamlendra.awasthi@gmail.com [Malaviya National Institute of Technology, Department of Physics (India); John, P. J., E-mail: placheriljohn@yahoo.com [University of Rajasthan, Department of Zoology (India)

    2013-09-15

    Silver nanoparticles (Ag NPs) are being used increasingly in wound dressings, catheters, and in various household products due to their antimicrobial activity. The present study reports the toxicity evaluation of synthesized and well characterized Ag NPs using Chinese hamster ovary (CHO) cells. The UV-Vis spectroscopy reveals the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 408-410 nm. Transmission electron microscopy (TEM) reveals that the average diameter of silver nanoparticles is about 5.0 {+-} 1.0 nm and that they have spherical shape. Cell visibility and cell viability percentage show dose-dependent cellular toxicity of Ag NPs. The half maximal inhibitory concentration (IC{sub 50}) for CHO cells is 68.0 {+-} 2.65 {mu}g/ml after 24 h Ag NPs exposure. Toxicity evaluations, including cellular morphology, mitochondrial function (MTT assay), reactive oxygen species (ROS), and DNA fragmentation assay (Ladder pattern) were assessed in unexposed CHO cells (control) and the cells exposed to Ag NPs concentrations of 15, 30, and 60 {mu}g/ml for 24 h. The findings may assist in the designing of Ag NPs for various applications and provide insights into their toxicity.

  20. The GalNAc-type O-Glycoproteome of CHO Cells Characterized by the SimpleCell Strategy

    DEFF Research Database (Denmark)

    Zhang, Yang; Halim, Adnan; Narimatsu, Yoshiki;

    2014-01-01

    of glycan structures (glycostructures) on glycoproteins are well established, our knowledge of the capacity of CHO cells for attaching GalNAc-type O-glycans to proteins (glycosites) is minimal. This type of O-glycosylation is one of the most abundant forms of glycosylation, and it is differentially...... regulated in cells by expression of a subset of homologous polypeptide GalNAc-transferases. Here, we have genetically engineered CHO cells to produce homogeneous truncated O-glycans, so-called SimpleCells, which enabled lectin enrichment of O-glycoproteins and characterization of the O-glycoproteome. We...

  1. Cell survival and chromosomal aberrations in CHO-K1 cells irradiated by carbon ions.

    Science.gov (United States)

    Czub, J; Banaś, D; Błaszczyk, A; Braziewicz, J; Buraczewska, I; Choiński, J; Górak, U; Jaskóła, M; Korman, A; Lankoff, A; Lisowska, H; Łukaszek, A; Szefliński, Z; Wójcik, A

    2009-03-01

    Chinese hamster ovary CHO-K1 cells were exposed to high LET (12)C-beam (LET: 830 keV/microm) in the dose range of 0-6 Gy and to (60)Co irradiation and the RBE value was obtained. Effects of (12)C-beam exposure on cell survival and chromosomal aberrations were calculated. The chromosomal aberration data were fitted with linear equation. The distribution of aberration in cells was examined with a standard u-test and used to evaluate the data according to Poisson probabilities. The variance to the mean ratio sigma(2)/Y and the dispersion index (u) were determined. Overdispersion was significant (p<0.05) when the value of u exceeded 1.96.

  2. Expression of GPI anchored human recombinant erythropoietin in CHO cells is devoid of glycosylation heterogeneity.

    Science.gov (United States)

    Singh, Pankaj Kumar; Devasahayam, Mercy; Devi, Sobita

    2015-04-01

    Erythropoietin is a glycohormone involved in the regulation of the blood cell levels. It is a 166 amino acid protein having 3 N-glycosylation and one O-linked glycosylation sites, and is used to treat anaemia related illness. Though human recombinant erythropoietin (rEPO) is produced in CHO cells, the loss in quality control is 80% due to incomplete glycosylation of the rEPO with low levels of fully glycosylated active rEPO. Here, we describe the expression from CHO cells of fully glycosylated human rEPO when expressed as a GPI anchored molecule (rEPO-g). The results demonstrated the production of a homogenous completely glycosylated human rEPO-g as a 42 kD band without any low molecular weight glycoform variants as shown by affinity chromatography followed by SDS-PAGE and anti-human EPO specific western blot. The western blot using specific monoclonal antibody is the available biochemical technique to prove the presence of homogeneity in the expressed recombinant protein. The GPI anchor can be removed during the purification process to yield a therapeutically relevant recombinant erythropoietin molecule cells with a higher in vivo biological activity due to its high molecular weight of 40 kD. This is possibly the first report on the production of a homogenous and completely glycosylated human rEPO from CHO cells for efficient therapy.

  3. Elucidating the role of copper in CHO cell energy metabolism using (13)C metabolic flux analysis.

    Science.gov (United States)

    Nargund, Shilpa; Qiu, Jinshu; Goudar, Chetan T

    2015-01-01

    (13)C-metabolic flux analysis was used to understand copper deficiency-related restructuring of energy metabolism, which leads to excessive lactate production in recombinant protein-producing CHO cells. Stationary-phase labeling experiments with U-(13)C glucose were conducted on CHO cells grown under high and limiting copper in 3 L fed-batch bioreactors. The resultant labeling patterns of soluble metabolites were measured by GC-MS and used to estimate metabolic fluxes in the central carbon metabolism pathways using OpenFlux. Fluxes were evaluated 300 times from stoichiometrically feasible random guess values and their confidence intervals calculated by Monte Carlo simulations. Results from metabolic flux analysis exhibited significant carbon redistribution throughout the metabolic network in cells under Cu deficiency. Specifically, glycolytic fluxes increased (25%-79% relative to glucose uptake) whereas fluxes through the TCA and pentose phosphate pathway (PPP) were lower (15%-23% and 74%, respectively) compared with the Cu-containing condition. Furthermore, under Cu deficiency, 33% of the flux entering TCA via the pyruvate node was redirected to lactate and malate production. Based on these results, we hypothesize that Cu deficiency disrupts the electron transport chain causing ATP deficiency, redox imbalance, and oxidative stress, which in turn drive copper-deficient CHO cells to produce energy via aerobic glycolysis, which is associated with excessive lactate production, rather than the more efficient route of oxidative phosphorylation.

  4. BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

    Institute of Scientific and Technical Information of China (English)

    ZHANGHong; ZHUHesun; 等

    2001-01-01

    The surface of polypropylene(PP) membrane was modified by low temperature plasma with ammonia.The effect of exposure time was investigated by means of contact angle measurement.The results show that low temperature ammonia plasma treatment can enhance its hydrophilicity.Chinese hamster ovary(CHO)cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.

  5. Expression of orphan G-protein coupled receptor GPR174 in CHO cells induced morphological changes and proliferation delay via increasing intracellular cAMP

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Kazuya; Yamamura, Chiaki; Tabata, Ken-ichi [Laboratory of Pharmacoinformatics, Graduate School of Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Fujita, Norihisa, E-mail: nori@ph.ritsumei.ac.jp [Laboratory of Pharmacoinformatics, Graduate School of Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); School of Pharmacy, Ristumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Expression of GPR174 in CHO cells induces morphological changes and proliferation delay. Black-Right-Pointing-Pointer These are due to increase in intracellular cAMP concentration. Black-Right-Pointing-Pointer Lysophosphatidylserine was identified to stimulate GPR174 leading to activate ACase. Black-Right-Pointing-Pointer The potencies of fatty acid moiety on LysoPS were oleoyl Greater-Than-Or-Slanted-Equal-To stearoyl > palmitoyl. Black-Right-Pointing-Pointer We propose that GPR174 is a lysophosphatidylserine receptor. -- Abstract: We established cell lines that stably express orphan GPCR GPR174 using CHO cells, and studied physiological and pharmacological features of the receptor. GPR174-expressing cells showed cell-cell adhesion with localization of actin filaments to cell membrane, and revealed significant delay of cell proliferation. Since the morphological changes of GPR174-cells were very similar to mock CHO cells treated with cholera toxin, we measured the concentration of intracellular cAMP. The results showed the concentration was significantly elevated in GPR174-cells. By measuring intracellular cAMP concentration in GPR174-cells, we screened lipids and nucleotides to identify ligands for GPR174. We found that lysophosphatidylserine (LysoPS) stimulated increase in intracellular cAMP in a dose-dependent manner. Moreover, phosphorylation of Erk was elevated by LysoPS in GPR174 cells. These LysoPS responses were inhibited by NF449, an inhibitor of G{alpha}{sub s} protein. These results suggested that GPR174 was a putative LysoPS receptor conjugating with G{alpha}{sub s}, and its expression induced morphological changes in CHO cells by constitutively activating adenylyl cycles accompanied with cell conjunctions and delay of proliferation.

  6. Improved recombinant antibody production by CHO cells using a production enhancer DNA element with repeated transgene integration at a predetermined chromosomal site.

    Science.gov (United States)

    Kawabe, Yoshinori; Inao, Takanori; Komatsu, Shodai; Huang, Guan; Ito, Akira; Omasa, Takeshi; Kamihira, Masamichi

    2017-03-01

    Chinese hamster ovary (CHO) cells are one of the most useful host cell lines for the production of biopharmaceutical proteins. Although a series of production processes have been refined to improve protein productivity and cost performance, establishing producer cells is still time-consuming and labor-intensive. Recombinase-mediated site-specific gene integration into a predetermined chromosomal locus may enable predictable protein expression, reducing the laborious process of cell screening. We previously developed an accumulative site-specific gene integration system (AGIS) using Cre recombinase and mutated loxP sites for transgene integration and amplification in the CHO cell genome. Epigenetic modifier elements such as insulators are effective DNA cis-regulatory elements for stabilizing transgene expression. Here, we attempted to enhance transgene expression in recombinant CHO cells generated by AGIS using a production enhancer DNA element (PE) derived from the CHO genome. The PE was introduced into an expression unit for a recombinant scFv-Fc antibody. The effect on scFv-Fc productivity of PE position and orientation within the transgene was evaluated, while keeping the background chromosomal structure constant. For the optimal PE arrangement, scFv-Fc productivity was enhanced 2.6-fold compared with an expression unit without a PE. The enhancing effect of the PE on transgene expression was also observed when two or three PE-flanked expression units were inserted as tandem repeats. These results indicate that AGIS using the PE-flanked expression unit is a promising approach for establishing producer cell lines for biopharmaceutical protein production.

  7. Fucan inhibits Chinese hamster ovary cell (CHO) adhesion to fibronectin by binding to the extracellular matrix.

    Science.gov (United States)

    Rocha, Hugo A; Franco, Célia R; Trindade, Edvaldo S; Veiga, Silvio S; Leite, Edda L; Nader, Helena B; Dietrich, Carl P

    2005-07-01

    In recent years, sulfated fucans have emerged as an important class of natural biopolymers. In this study, the anti-adhesive activity of a fucan from the brown seaweed Spatoglossum schröederi was analyzed using tumorigenic cells: wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). Fibronectin (FN) was used as substrate for cell attachment. For both cell types, this fucan has shown a dose-dependent anti-adhesive effect, reaching saturation at around 400 mug/mL. This effect was abolished by desulfation of the fucan. In addition, this polymer exhibited the highest inhibitory effect in comparison to other sulfated polysaccharides. The fucan was biotinylated and used as a probe to identify its action sites. Biotinylated fucan was detected in the extracellular matrix environment by confocal microscopy and flow cytometric analysis, but not at the cell surface. The results suggest that the fucan shows anti-adhesive activity by binding directly to FN, and blocking FN sites that are recognized by cell surface ligands, possibly the integrin family.

  8. Stable expression of human thyrotropin (hTSH) in mammalian cells (CHO) expressing {alpha}2,6 sialyltransferase; Expressao estavel tireotrofina humana (r-hTSH) em celulas de mamifero (CHO) que expressam {alpha}2,6 sialiltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Damiani, Renata

    2009-07-01

    A CHO cell line, previously genetically modified by the introduction of rat {alpha}2,6-sialyltransferase cDNA, generated for the first time a human-like sialylated recombinant hTSH (hlsr-hTSH) more similar to the native hormone, with 61% of {alpha}2,3- and 39% of {alpha}2,6-linked sialic acid residues. The best clone, when submitted to gene amplification with up to 8 {mu}M methotrexate, presented a secretion level of {approx}2 {mu}g hTSH/10{sup 6} cells/day, useful for product purification and characterization. The relative molecular masses (M{sub r}) of the heterodimer and of the {alpha}- and {beta}-subunits of purified hlsr-hTSH, determined by MALDI-TOF mass spectrometry, and the relative hydrophobicities, determined by RP-HPLC, were not remarkably different from those presented by two r-hTSH preparations secreted by normal CHO cells. Some differences were observed, though, in N-glycan composition, with more tri- and much more tetra-sialylated structures in hlsr-hTSH. When analyzed via an in vivo bioassay based on hTSH-induced T{sub 4} release in mice, hlsr-hTSH was shown to be equipotent (p > 0.05) with the commercial preparation of r-hTSH (Thyrogen), and 1.5-fold more potent than native hTSH (p < 0.001). (author)

  9. C-terminal KDEL-modified cystatin C is retained in transfected CHO cells

    DEFF Research Database (Denmark)

    Johansen, Teit Eliot; Vogel, Charlotte Katrine; Schwartz, Thue W.

    1990-01-01

    The significance of a C-terminal tetrapeptide, Lys-Asp-Glu-Leu (KDEL), as a retention signal for the endoplasmatic reticulum was studied using cystatin C, a general thiol protease inhibitor, as the reporter protein. Clones of CHO cells were analyzed after stable transfection with eukaryotic...... expression vectors encoding either cystatin C, KDEL extended cystatin C, or cystatin C extended with a control sequence. It is concluded that cystatin C with the KDEL tetrapeptide as a C-terminal extension is retained intracellularly without apparent accumulation of the molecule....

  10. A Single Dynamic Metabolic Model Can Describe mAb Producing CHO Cell Batch and Fed-Batch Cultures on Different Culture Media.

    Science.gov (United States)

    Robitaille, Julien; Chen, Jingkui; Jolicoeur, Mario

    2015-01-01

    CHO cell culture high productivity relies on optimized culture medium management under fed-batch or perfused chemostat strategies enabling high cell densities. In this work, a dynamic metabolic model for CHO cells was further developed, calibrated and challenged using datasets obtained under four different culture conditions, including two batch and two fed-batch cultures comparing two different culture media. The recombinant CHO-DXB11 cell line producing the EG2-hFc monoclonal antibody was studied. Quantification of extracellular substrates and metabolites concentration, viable cell density, monoclonal antibody concentration and intracellular concentration of metabolite intermediates of glycolysis, pentose-phosphate and TCA cycle, as well as of energetic nucleotides, were obtained for model calibration. Results suggest that a single model structure with a single set of kinetic parameter values is efficient at simulating viable cell behavior in all cases under study, estimating the time course of measured and non-measured intracellular and extracellular metabolites. Model simulations also allowed performing dynamic metabolic flux analysis, showing that the culture media and the fed-batch strategies tested had little impact on flux distribution. This work thus paves the way to an in silico platform allowing to assess the performance of different culture media and fed-batch strategies.

  11. Homologous Recombination-Independent Large Gene Cassette Knock-in in CHO Cells Using TALEN and MMEJ-Directed Donor Plasmids

    Directory of Open Access Journals (Sweden)

    Tetsushi Sakuma

    2015-10-01

    Full Text Available Gene knock-in techniques have rapidly evolved in recent years, along with the development and maturation of genome editing technology using programmable nucleases. We recently reported a novel strategy for microhomology-mediated end-joining-dependent integration of donor DNA by using TALEN or CRISPR/Cas9 and optimized targeting vectors, named PITCh (Precise Integration into Target Chromosome vectors. Here we describe TALEN and PITCh vector-mediated integration of long gene cassettes, including a single-chain Fv-Fc (scFv-Fc gene, in Chinese hamster ovary (CHO cells, with comparison of targeting and cloning efficiency among several donor design and culture conditions. We achieved 9.6-kb whole plasmid integration and 7.6-kb backbone-free integration into a defined genomic locus in CHO cells. Furthermore, we confirmed the reasonable productivity of recombinant scFv-Fc protein of the knock-in cells. Using our protocol, the knock-in cell clones could be obtained by a single transfection and a single limiting dilution using a 96-well plate, without constructing targeting vectors containing long homology arms. Thus, the study described herein provides a highly practical strategy for gene knock-in of large DNA in CHO cells, which accelerates high-throughput generation of cell lines stably producing any desired biopharmaceuticals, including huge antibody proteins.

  12. Effects of aldicarb and propoxur on cytotoxicity and lipid peroxidation in CHO-K1 cells.

    Science.gov (United States)

    Maran, E; Fernández-Franzón, M; Font, G; Ruiz, M J

    2010-06-01

    Cytotoxic effects of aldicarb, its sulfone and sulfoxide, and propoxur, lipid peroxidation and antioxidant parameters in Chinese Hamster Ovary (CHO-K1) cells were determined. D,L-buthionine-(S,R)-sulfoximine (BSO) was assayed to determine the role of GSH in the protection against carbamate cytotoxicity. Pre-treatment with 60 microM BSO, induced a significant decrease in the glutathione reductase (GR; 64-141%), the glutathione peroxidase (GPx; 10-30%) and the glutathione S-transferase (GST; 59-93%) activities, and its GSH levels (79-85%), while the oxidized glutathione (GSSG) levels significantly increased (64-78%) respect to experiment non-BSO-pretreated. Carbamates BSO pre-treated vs. non-BSO pre-treated showed a significant increase in malondialdehyde (MDA) production (from 13% to 52% vs. 25% to 93%). These data suggest that carbamates could injure CHO-K1 cells via oxidative stress by the increase of MDA production; moreover, BSO enhance the oxidative damage caused by carbamates. However, the glutathione system protects cells from carbamates damage.

  13. Accelerating genome editing in CHO cells using CRISPR Cas9 and CRISPy, a web-based target finding tool.

    Science.gov (United States)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Hansen, Henning Gram; Kallehauge, Thomas Beuchert; Betenbaugh, Michael J; Nielsen, Alex Toftgaard; Kildegaard, Helene Faustrup

    2014-08-01

    Chinese hamster ovary (CHO) cells are widely used in the biopharmaceutical industry as a host for the production of complex pharmaceutical proteins. Thus genome engineering of CHO cells for improved product quality and yield is of great interest. Here, we demonstrate for the first time the efficacy of the CRISPR Cas9 technology in CHO cells by generating site-specific gene disruptions in COSMC and FUT8, both of which encode proteins involved in glycosylation. The tested single guide RNAs (sgRNAs) created an indel frequency up to 47.3% in COSMC, while an indel frequency up to 99.7% in FUT8 was achieved by applying lectin selection. All eight sgRNAs examined in this study resulted in relatively high indel frequencies, demonstrating that the Cas9 system is a robust and efficient genome-editing methodology in CHO cells. Deep sequencing revealed that 85% of the indels created by Cas9 resulted in frameshift mutations at the target sites, with a strong preference for single base indels. Finally, we have developed a user-friendly bioinformatics tool, named "CRISPy" for rapid identification of sgRNA target sequences in the CHO-K1 genome. The CRISPy tool identified 1,970,449 CRISPR targets divided into 27,553 genes and lists the number of off-target sites in the genome. In conclusion, the proven functionality of Cas9 to edit CHO genomes combined with our CRISPy database have the potential to accelerate genome editing and synthetic biology efforts in CHO cells.

  14. Construction of BAC-based physical map and analysis of chromosome rearrangement in Chinese hamster ovary cell lines.

    Science.gov (United States)

    Cao, Yihua; Kimura, Shuichi; Itoi, Takayuki; Honda, Kohsuke; Ohtake, Hisao; Omasa, Takeshi

    2012-06-01

    Chinese hamster ovary (CHO) cells have frequently been used in biotechnology for many years as a mammalian host cell platform for cloning and expressing genes of interest. A detailed physical chromosomal map of the CHO DG44 cell line was constructed by fluorescence in situ hybridization (FISH) imaging using randomly selected 303 BAC clones as hybridization probes (BAC-FISH). The two longest chromosomes were completely paired chromosomes; other chromosomes were partly deleted or rearranged. The end sequences of 624 BAC clones, including 287 mapped BAC clones, were analyzed and 1,119 informative BAC end sequences were obtained. Among 303 mapped BAC clones, 185 clones were used for BAC-FISH analysis of CHO K1 chromosomes and 94 clones for primary Chinese hamster lung cells. Based on this constructed physical map and end sequences, the chromosome rearrangements between CHO DG44, CHO K1, and primary Chinese hamster cells were investigated. Among 20 CHO chromosomes, eight were conserved without large rearrangement in CHO DG44, CHO K1, and primary Chinese hamster cells. This result suggested that these chromosomes were stable and essential in CHO cells and supposedly conserved in other CHO cell lines.

  15. ARP2, a novel pro-apoptotic protein expressed in epithelial prostate cancer LNCaP cells and epithelial ovary CHO transformed cells.

    Directory of Open Access Journals (Sweden)

    Jaime Mas-Oliva

    Full Text Available Neoplastic epithelial cells generate the most aggressive types of cancers such as those located in the lung, breast, colon, prostate and ovary. During advanced stages of prostate cancer, epithelial cells are associated to the appearance of androgen-independent tumors, an apoptotic-resistant phenotype that ultimately overgrows and promotes metastatic events. We have previously identified and electrophysiologically characterized a novel Ca(2+-permeable channel activated during apoptosis in the androgen-independent prostate epithelial cancer cell line, LNCaP. In addition, we reported for the first time the cloning and characterization of this channel-like molecule named apoptosis regulated protein 2 (ARP2 associated to a lethal influx of Ca(2+ in Xenopus oocytes. In the present study, LNCaP cells and Chinese hamster ovary cells (CHO cell line transfected with arp2-cDNA are induced to undergo apoptosis showing an important impact on cell viability and activation of caspases 3 and 7 when compared to serum deprived grown cells and ionomycin treated cells. The subcellular localization of ARP2 in CHO cells undergoing apoptosis was studied using confocal microscopy. While apoptosis progresses, ARP2 initially localized in the peri-nuclear region of cells migrates with time towards the plasma membrane region. Based on the present results and those of our previous studies, the fact that ARP2 constitutes a novel cation channel is supported. Therefore, ARP2 becomes a valuable target to modulate the influx and concentration of calcium in the cytoplasm of epithelial cancer cells showing an apoptotic-resistant phenotype during the onset of an apoptotic event.

  16. Engineer medium and feed for modulating N-glycosylation of recombinant protein production in CHO cell culture

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    2016-01-01

    -glycosylation is crucial, as the structure of N-glycans can largely influence both biological and physicochemical properties of recombinant proteins. Protein N-glycosylation in CHO cell culture can be controlled and tuned by engineering medium, feed, culture process, as well as genetic elements of the cell......Chinese hamster ovary (CHO) cells have become the primary expression system for the production of complex recombinant proteins due to their long-term success in industrial scale production and generating appropriate protein N-glycans similar to that of humans. Control and optimization of protein N...

  17. Genomic landscapes of Chinese hamster ovary cell lines as revealed by the Cricetulus griseus draft genome.

    Science.gov (United States)

    Lewis, Nathan E; Liu, Xin; Li, Yuxiang; Nagarajan, Harish; Yerganian, George; O'Brien, Edward; Bordbar, Aarash; Roth, Anne M; Rosenbloom, Jeffrey; Bian, Chao; Xie, Min; Chen, Wenbin; Li, Ning; Baycin-Hizal, Deniz; Latif, Haythem; Forster, Jochen; Betenbaugh, Michael J; Famili, Iman; Xu, Xun; Wang, Jun; Palsson, Bernhard O

    2013-08-01

    Chinese hamster ovary (CHO) cells, first isolated in 1957, are the preferred production host for many therapeutic proteins. Although genetic heterogeneity among CHO cell lines has been well documented, a systematic, nucleotide-resolution characterization of their genotypic differences has been stymied by the lack of a unifying genomic resource for CHO cells. Here we report a 2.4-Gb draft genome sequence of a female Chinese hamster, Cricetulus griseus, harboring 24,044 genes. We also resequenced and analyzed the genomes of six CHO cell lines from the CHO-K1, DG44 and CHO-S lineages. This analysis identified hamster genes missing in different CHO cell lines, and detected >3.7 million single-nucleotide polymorphisms (SNPs), 551,240 indels and 7,063 copy number variations. Many mutations are located in genes with functions relevant to bioprocessing, such as apoptosis. The details of this genetic diversity highlight the value of the hamster genome as the reference upon which CHO cells can be studied and engineered for protein production.

  18. 电子烟烟气捕集液对 CHO 细胞相对增殖率的影响%Effect of Electronic Cigarette Smoke in Cell Culture Medium on Relative Growth Rate of Cell CHO

    Institute of Scientific and Technical Information of China (English)

    曾婉俐; 高茜; 杨叶昆; 夭建华; 宋春满; 李雪梅

    2015-01-01

    参照加拿大 Labstat 的电子烟抽吸模式,抽吸100口电子烟,用细胞培养基捕集电子烟烟气,通过 MTT 法研究电子烟烟气对 CHO 细胞相对增殖率的影响。结果表明:在该抽吸模式下,抽吸100口电子烟产生的烟气捕集液与CHO 细胞相对增殖率之间存在浓度梯度效应;抽吸一支3R4F 产生的烟气捕集液对 CHO 细胞相对增殖率的影响明显高于抽吸100口电子烟所产生烟气的影响,在100%烟气浓度下,电子烟烟气捕集液对 CHO 细胞的相对增殖率是3R4F的10倍以上。%Based on Canada Labstat electronic cigarette suction mode,every 100 puffs of electronic cigarette smoke were trapped into cell culture medium,effect of electronic cigarette smoke on relative growth rate(RGR) of cell CHO was studied via MTT assay.Results showed that,in this suction mode,there were concentration gradient effect between RGR of cell CHO and 100 puffs of electronic cigarette smoke in cell culture medium,one 3R4F had higher effect than 100 puffs electronic cigarette,the RGR of 100 puffs of electronic cigarette smoke in cell culture medium was more than 10 times of one 3R4F at concentration of 100%.

  19. Fibrinogen interaction of CHO cells expressing chimeric αIIb/αvβ3 integrin

    Institute of Scientific and Technical Information of China (English)

    Juan-juan CHEN; Xiao-yu SU; Xiao-dong XI; Li-ping LIN; Jian DING; He LU

    2008-01-01

    Aim: The molecular mechanisms of the affinity regulation of αvβ3 integrin are important in tumor development, wound repairing, and angiogenesis. It has been established that the cytoplasmic domains of αvβ3 integrin play an important role in integrin-ligand affinity regulation. However, the relationship of structure-func-tion within these domains remains unclear. Methods: The extracellular and trans-membrane domain of αⅡb was fused to the αv integrin cytoplasmic domain, and the chimeric α subunit was coexpressed in Chinese hamster ovary (CHO) cells with the wild-type β3 subunit or with 3 mutant 133 sequences bearing truncations at the positions of T741, Y747, and F754, respectively. The CHO cells expressing these recombinant integrins were tested for soluble fibrinogen binding and the cell adhesion and spreading on immobilized fibrinogen. Results: All 4 types of integrins bound soluble fibrinogen in the absence of agonist stimulation, and only the cells expressing the chimeric α subunit with the wild-type β3 subunit, but not those with truncated β3, could adhere to and spread on immobilized fibrinogen. Conclusion: The substitution αⅡb at the cytoplasmic domain with the ctv cyto-plasmic sequence rendered the extracellular αⅡbβ3 a constitutively activated con-formation for ligands without the need of "inside-out" signals. Our results also indicated that the COOH-terminal sequence of β3 might play a key role in integrin αⅡb/αvβ3-mediated cell adhesion and spreading on immobilized fibrinogen. The cells expressing αⅡb/αvβ3 have enormous potential for facilitating drug screen-ing for antagonists either to αvβ3 intracellular interactions or to αⅡbβ3 receptor functions.

  20. Analysis of CHO cells metabolic redistribution in a glutamate-based defined medium in continuous culture.

    Science.gov (United States)

    Altamirano, C; Illanes, A; Casablancas, A; Gámez, X; Cairó, J J; Gòdia, C

    2001-01-01

    The effect of glutamine replacement by glutamate and the balance between glutamate and glucose metabolism on the redistribution of t-PA-producing recombinant CHO cells metabolism is studied in a series of glucose shift down and shift up experiments in continuous culture. These experiments reveal the existence of multiple steady states, and experimental data are used to perform metabolic flux analysis to gain a better insight into cellular metabolism and its redistribution. Regulation of glucose feed rate promotes a higher efficiency of glucose and nitrogen source utilization, with lower production of metabolic byproducts, but this reduces t-PA specific production rate. This reduction under glucose limitation can be attributed to the fact that the cells are forced to efficiently utilize the carbon and energy source for growth, impairing the production of dispensable metabolites. It is, therefore, the combination of growth rate and carbon and energy source availability that determines the level of t-PA production in continuous culture.

  1. Combinatorial treatment with lithium chloride enhances recombinant antibody production in transiently transfected CHO and HEK293E cells

    DEFF Research Database (Denmark)

    Kim, Che Lin; Kwang Ha, Tae; Min Lee, Gyun

    2016-01-01

    Lithium chloride (LiCl), which induces cell cycle arrest at G2/M phase, is known as a specific production rate (qp)-enhancing additive in recombinant Chinese hamster ovary (CHO) cell culture. To determine the potential of LiCl as a chemical additive that enhances transient gene expression (TGE), ...

  2. A control strategy to investigate the relationship between specific productivity and high-mannose glycoforms in CHO cells.

    Science.gov (United States)

    Zalai, Dénes; Hevér, Helga; Lovász, Krisztina; Molnár, Dóra; Wechselberger, Patrick; Hofer, Alexandra; Párta, László; Putics, Ákos; Herwig, Christoph

    2016-08-01

    The integration of physiological knowledge into process control strategies is a cornerstone for the improvement of biopharmaceutical cell culture technologies. The present contribution investigates the applicability of specific productivity as a physiological control parameter in a cell culture process producing a monoclonal antibody (mAb) in CHO cells. In order to characterize cell physiology, the on-line oxygen uptake rate (OUR) was monitored and the time-resolved specific productivity was calculated as physiological parameters. This characterization enabled to identify the tight link between the deprivation of tyrosine and the decrease in cell respiration and in specific productivity. Subsequently, this link was used to control specific productivity by applying different feeding profiles. The maintenance of specific productivity at various levels enabled to identify a correlation between the rate of product formation and the relative abundance of high-mannose glycoforms. An increase in high mannose content was assumed to be the result of high specific productivity. Furthermore, the high mannose content as a function of cultivation pH and specific productivity was investigated in a design of experiment approach. This study demonstrated how physiological parameters could be used to understand interactions between process parameters, physiological parameters, and product quality attributes.

  3. Multigene expression in stable CHO cell pools generated with the piggyBac transposon system.

    Science.gov (United States)

    Balasubramanian, Sowmya; Wurm, Florian M; Hacker, David L

    2016-09-01

    Heterogenous populations of recombinant cells (cell pools) stably expressing 1-4 transgenes were generated from Chinese hamster overy (CHO) cells with the piggyBac (PB) transposon system. The cell pools produced different combinations of three model proteins-enhanced green fluorescent protein (EGFP), secreted alkaline phosphatase (SEAP), and a monoclonal IgG1 antibody. Each transgene was present on a separate PB donor plasmid with either the same or a different selection gene. In both cases, we obtained PB-derived cell pools with higher recombinant protein yields than from cell pools generated by conventional gene delivery. In PB-derived cell pools generated using a single selection agent, both protein production and the number of integrated copies of each transgene declined as the number of transfected transgenes increased. However, the total number of integrated transgenes was similar regardless of the number of different transgenes transfected. For PB-derived cell pools generated by selection of each transgene with a different selection agent, the total number of integrated transgenes increased with the number of transfected transgenes. The results suggest that the generation of cell pools producing multiple recombinant proteins is feasible and that the method is more efficient when each individual transgene is selected with a different marker. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1308-1317, 2016.

  4. Performance evaluation of CHO-K1 cell in culture medium supplemented with hemolymph

    Directory of Open Access Journals (Sweden)

    Tássia Raffoul

    2005-06-01

    Full Text Available The aim of this work was to evaluate the potential of hemolymph utilization as a culture medium supplement to cultivate the animal cell CHO-K1. For this purpose 1% v/v of hemolymph was added to DMEM medium containing 10% v/v of FBS and 1 or 4.5 g/L of glucose. The culture was grown in spinner flasks incubated in a 10% v/v CO2 environment, at 37ºC, with the Cytodex 1 microcarrier. Comparing the results obtained from the culture with hemolymph against those without hemolymph, a positive influence of the hemolymph was observed, as the experiment with hemolymph presented a 52% higher cell concentration and a higher productivity of up to 40%.Desenvolvimento de meios de cultura isentos de soro fetal bovino (SFB é uma das grandes prioridades de pesquisa em desenvolvimento de processos com célula animal. O objetivo do presente trabalho foi realizar uma análise do potencial de uso da hemolinfa como suplemento do meio utilizado no cultivo da célula animal ancorante CHO-K1. Para isso, foi adicionado 1% v/v de extrato de hemolinfa ao meio DMEM contendo 10% v/v de SFB e 1,0 ou 4,5 g/L de glicose. O cultivo foi realizado em frascos tipo spinner em um ambiente de 10% v/v de CO2, a 37ºC, utilizando o microcarregador Cytodex 1. Comparando os resultados obtidos no ensaio com hemolinfa com um sem hemolinfa pode-se notar uma influência positiva da hemolinfa no cultivo, já que o ensaio com hemolinfa apresentou uma concentração máxima de células 52% maior e uma produtividade máxima de até 40% maior.

  5. Accelerating Genome Editing in CHO Cells Using CRISPR Cas9 and CRISPy, a Web-Based Target Finding Tool

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Hansen, Henning Gram

    2014-01-01

    by applying lectin selection. All eight sgRNAs examined in this study resulted in relatively high indel frequencies, demonstrating that the Cas9 system is a robust and efficient genomeediting methodology in CHO cells. Deep sequencing revealed that 85% of the indels created by Cas9 resulted in frameshift...

  6. Role of the Nfa1 protein in pathogenic Naegleria fowleri cocultured with CHO target cells.

    Science.gov (United States)

    Kang, Su-Yeon; Song, Kyoung-Ju; Jeong, Seok-Ryoul; Kim, Jong-Hyun; Park, Sun; Kim, Kyongmin; Kwon, Myung-Hee; Shin, Ho-Joon

    2005-07-01

    Naegleria fowleri, a free-living amoeba, exists as a virulent pathogen which causes fatal primary amoebic meningoencephalitis in experimental animals and humans. Using infected and immune mouse sera, we previously cloned an nfa1 gene from a cDNA library of N. fowleri by immunoscreening. The nfa1 gene (360 bp) produced a recombinant 13.1-kDa protein, and the Nfa1 protein showed pseudopodium-specific immunolocalization on a trophozoite of N. fowleri. In this study, the role of the Nfa1 protein as a cell contact mechanism of N. fowleri cocultured with target cells was observed by an immunofluorescence assay with an anti-Nfa1 polyclonal antibody. Using confocal microscopic findings, the Nfa1 protein was located on the pseudopodia of N. fowleri trophozoites. The Nfa1 protein in N. fowleri trophozoites cocultured with CHO target cells was also located on pseudopodia, as well as in a food cup formed as a phagocytic structure in close contact with target cells. The amount of nfa1 mRNA of N. fowleri was strongly increased 6 h after coculture.

  7. Microparticle-mediated transfer of the viral receptors CAR and CD46, and the CFTR channel in a CHO cell model confers new functions to target cells.

    Directory of Open Access Journals (Sweden)

    Gaëlle Gonzalez

    Full Text Available Cell microparticles (MPs released in the extracellular milieu can embark plasma membrane and intracellular components which are specific of their cellular origin, and transfer them to target cells. The MP-mediated, cell-to-cell transfer of three human membrane glycoproteins of different degrees of complexity was investigated in the present study, using a CHO cell model system. We first tested the delivery of CAR and CD46, two monospanins which act as adenovirus receptors, to target CHO cells. CHO cells lack CAR and CD46, high affinity receptors for human adenovirus serotype 5 (HAdV5, and serotype 35 (HAdV35, respectively. We found that MPs derived from CHO cells (MP-donor cells constitutively expressing CAR (MP-CAR or CD46 (MP-CD46 were able to transfer CAR and CD46 to target CHO cells, and conferred selective permissiveness to HAdV5 and HAdV35. In addition, target CHO cells incubated with MP-CD46 acquired the CD46-associated function in complement regulation. We also explored the MP-mediated delivery of a dodecaspanin membrane glycoprotein, the CFTR to target CHO cells. CFTR functions as a chloride channel in human cells and is implicated in the genetic disease cystic fibrosis. Target CHO cells incubated with MPs produced by CHO cells constitutively expressing GFP-tagged CFTR (MP-GFP-CFTR were found to gain a new cellular function, the chloride channel activity associated to CFTR. Time-course analysis of the appearance of GFP-CFTR in target cells suggested that MPs could achieve the delivery of CFTR to target cells via two mechanisms: the transfer of mature, membrane-inserted CFTR glycoprotein, and the transfer of CFTR-encoding mRNA. These results confirmed that cell-derived MPs represent a new class of promising therapeutic vehicles for the delivery of bioactive macromolecules, proteins or mRNAs, the latter exerting the desired therapeutic effect in target cells via de novo synthesis of their encoded proteins.

  8. Differential effect of culture temperature and specific growth rate on CHO cell behavior in chemostat culture.

    Science.gov (United States)

    Vergara, Mauricio; Becerra, Silvana; Berrios, Julio; Osses, Nelson; Reyes, Juan; Rodríguez-Moyá, María; Gonzalez, Ramon; Altamirano, Claudia

    2014-01-01

    Mild hypothermia condition in mammalian cell culture technology has been one of the main focuses of research for the development of breeding strategies to maximize productivity of these production systems. Despite the large number of studies that show positive effects of mild hypothermia on specific productivity of r-proteins, no experimental approach has addressed the indirect effect of lower temperatures on specific cell growth rate, nor how this condition possibly affects less specific productivity of r-proteins. To separately analyze the effects of mild hypothermia and specific growth rate on CHO cell metabolism and recombinant human tissue plasminogen activator productivity as a model system, high dilution rate (0.017 h(-1)) and low dilution rate (0.012 h(-1)) at two cultivation temperatures (37 and 33 °C) were evaluated using chemostat culture. The results showed a positive effect on the specific productivity of r-protein with decreasing specific growth rate at 33 °C. Differential effect was achieved by mild hypothermia on the specific productivity of r-protein, contrary to the evidence reported in batch culture. Interestingly, reduction of metabolism could not be associated with a decrease in culture temperature, but rather with a decrease in specific growth rate.

  9. The emerging CHO systems biology era: harnessing the ‘omics revolution for biotechnology

    DEFF Research Database (Denmark)

    Kildegaard, Helene Faustrup; Baycin-Hizal, Deniz; Lewis, Nathan

    2013-01-01

    line was recently sequenced. Now, the CHO systems biology era is underway. Critical ‘omics data sets, including proteomics, transcriptomics, metabolomics, fluxomics, and glycomics, are emerging, allowing the elucidation of the molecular basis of CHO cell physiology. The incorporation of these data sets...... into mathematical models that describe CHO phenotypes will provide crucial biotechnology insights. As ‘omics technologies and computational systems biology mature, genome-scale approaches will lead to major innovations in cell line development and metabolic engineering, thereby improving protein production......Chinese hamster ovary (CHO) cells are the primary factories for biopharmaceuticals because of their capacity to correctly fold and post-translationally modify recombinant proteins compatible with humans. New opportunities are arising to enhance these cell factories, especially since the CHO-K1 cell...

  10. Application of dielectric spectroscopy for monitoring high cell density in monoclonal antibody producing CHO cell cultivations.

    Science.gov (United States)

    Párta, László; Zalai, Dénes; Borbély, Sándor; Putics, Akos

    2014-02-01

    The application of dielectric spectroscopy was frequently investigated as an on-line cell culture monitoring tool; however, it still requires supportive data and experience in order to become a robust technique. In this study, dielectric spectroscopy was used to predict viable cell density (VCD) at industrially relevant high levels in concentrated fed-batch culture of Chinese hamster ovary cells producing a monoclonal antibody for pharmaceutical purposes. For on-line dielectric spectroscopy measurements, capacitance was scanned within a wide range of frequency values (100-19,490 kHz) in six parallel cell cultivation batches. Prior to detailed mathematical analysis of the collected data, principal component analysis (PCA) was applied to compare dielectric behavior of the cultivations. PCA analysis resulted in detecting measurement disturbances. By using the measured spectroscopic data, partial least squares regression (PLS), Cole-Cole, and linear modeling were applied and compared in order to predict VCD. The Cole-Cole and the PLS model provided reliable prediction over the entire cultivation including both the early and decline phases of cell growth, while the linear model failed to estimate VCD in the later, declining cultivation phase. In regards to the measurement error sensitivity, remarkable differences were shown among PLS, Cole-Cole, and linear modeling. VCD prediction accuracy could be improved in the runs with measurement disturbances by first derivative pre-treatment in PLS and by parameter optimization of the Cole-Cole modeling.

  11. Deregulated c—myc expression in quiescent CHO cells induces target gene transcription and subsequent apoptotic phenotype

    Institute of Scientific and Technical Information of China (English)

    FANGCHANGMING; CANSHI; 等

    1999-01-01

    Human c-myc cDNA was fused with the hormonebinding domain (HBD) cDNA of murine estrogen receptor gene and the chimeric gene was introduced into the CHO cells.The fusion protein,c-MycER,becomes activated when the synthetic steroid,4-hydroxy-tamoxifen (OHT),binds HBD.Activated c-MycER,likely c-Myc,can induce quiescent CHO cells reentry into S phase and subsequent cell death under serum-free condition.In addition,the expression of some proposed c-myc target genes such as ODC,MrDb,cad,rccl and rcl were found to increase upon OHT induction before S phase entry and apoptosis,indicating that these target genes are involved in cell cycle regulation and/or apoptosis control.However,the mutant D106-143c-MycER protein does not have above activities.

  12. Caspase-3 and its inhibitor Ac-DEVD-CHO in rat lens epithelial cell apoptosis induced by hydrogen in vitro

    Institute of Scientific and Technical Information of China (English)

    姚克; 王凯军; 徐雯; 孙朝晖; 申屠形超; 邱培瑾

    2003-01-01

    Objective To investigate the role of caspase-3 and its inhibitor Ac-DEVD-CHO in rat lens epithelial cell apoptosis induced by hydrogen peroxide (H2O2) in vitro.Methods Rat lenses were incubated in modified Eagle' s medium containing 2 mmol/L H2O2 to induce apoptosis in vitro. Apoptosis in lens epithelial cells was assessed by transmission electron microscopy and annexin V-propidium iodide (PI) double staining flow cytometry after 12, 24 and 48 h of incubation. The activity of caspase-3 was analyzed by western blotting.Results Observations under transmission electron microscopy revealed that 2 mmol/L H2O2 could effectively induce lens epithelial cell apoptosis in vitro. Caspase-3 activity increased during cell apoptosis and the peak measurement occurred at 24 h after treatment with H2O2. Cell apoptosis was blocked by caspase-3 inhibitor Ac-DEVD-CHO.Conclusions The activation of caspase-3 plays an important role in executing apoptosis in H2O2-treated lens epithelial cells and in the formation of cataract. The caspase-3 inhibitor Ac-DEVD-CHO may effectively prevent lens epithelial cell apoptosis caused by oxidative injury.

  13. Use of a transfected and amplified Drosophila heat shock promoter construction for inducible production of toxic mouse c-myc proteins in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Wurm, F.M.; Gwinn, K.A.; Papoulas, O.; Pallavicini, M.; Kingston, R.E.

    1987-07-24

    After transfection and selection with methotrexate, CHO cell lines were established which contained up to 2000 copies of an expression vector for c-myc protein. The vector contained the Drosophila heat shock protein 70 (hsp70) promoter fused with the coding region of the mouse c-myc gene. Incubation of cells for up to 3 hours at 43/sup 0/C resulted in at least a 100-fold induction of recombinant c-myc mRNA. When cells were shifted back to 37/sup 0/C, within 1 to 4 hours, this RNA was translated into protein to yield about 250 ..mu..g per 10/sup 9/ cells. Cells died a few hours later, suggesting that high concentrations of intracellular c-myc are cytotoxic. 47 refs., 5 figs.

  14. Identification of active elementary flux modes in mitochondria using selectively permeabilized CHO cells.

    Science.gov (United States)

    Nicolae, Averina; Wahrheit, Judith; Nonnenmacher, Yannic; Weyler, Christian; Heinzle, Elmar

    2015-11-01

    Metabolic compartmentation is a key feature of mammalian cells. Mitochondria are the powerhouse of eukaryotic cells, responsible for respiration and the TCA cycle. We accessed the mitochondrial metabolism of the economically important Chinese hamster ovary (CHO) cells using selective permeabilization. We tested key substrates without and with addition of ADP. Based on quantified uptake and production rates, we could determine the contribution of different elementary flux modes to the metabolism of a substrate or substrate combination. ADP stimulated the uptake of most metabolites, directly by serving as substrate for the respiratory chain, thus removing the inhibitory effect of NADH, or as allosteric effector. Addition of ADP favored substrate metabolization to CO2 and did not enhance the production of other metabolites. The controlling effect of ADP was more pronounced when we supplied metabolites to the first part of the TCA cycle: pyruvate, citrate, α-ketoglutarate and glutamine. In the second part of the TCA cycle, the rates were primarily controlled by the concentrations of C4-dicarboxylates. Without ADP addition, the activity of the pyruvate carboxylase-malate dehydrogenase-malic enzyme cycle consumed the ATP produced by oxidative phosphorylation, preventing its accumulation and maintaining metabolic steady state conditions. Aspartate was taken up only in combination with pyruvate, whose uptake also increased, a fact explained by complex regulatory effects. Isocitrate dehydrogenase and α-ketoglutarate dehydrogenase were identified as the key regulators of the TCA cycle, confirming existent knowledge from other cells. We have shown that selectively permeabilized cells combined with elementary mode analysis allow in-depth studying of the mitochondrial metabolism and regulation.

  15. Gene Cloning of Murine α-Fetoprotein Gene and Construction of Its Eukaryotic Expression Vector and Expression in CHO Cells

    Institute of Scientific and Technical Information of China (English)

    易继林; 田耕

    2003-01-01

    To clone the murine α-fetoprotein (AFP) gene, construct the eukaryotic expression vector of AFP and express in CHO cells, total RNA were extracted from Hepa 1-6 cells, and then the murine α-fetoprotein gene was amplified by RT-PCR and cloned into the eukaryotic expression vector pcDNA3.1. The recombinant of vector was identified by restriction enzyme analysis and sequencing. A fter transient transfection of CHO cells with the vector, Western blotting was used to detect the expression of AFP. It is concluded that the 1.8kb murine α-fetoprotein gene was successfully cloned and its eukaryotic expression vector was successfully constructed.

  16. Glycoprofiling effects of media additives on IgG produced by CHO cells in fed-batch bioreactors

    DEFF Research Database (Denmark)

    Kildegaard, Helene Faustrup; Fan, Yuzhou; Wagtberg Sen, Jette

    2016-01-01

    . In this study, the effect on IgG N-glycosylation from feeding CHO cells with eight glycosylation precursors during cultivation was investigated. The study was conducted in fed-batch mode in bioreactors with biological replicates to obtain highly controlled and comparable conditions. We assessed charge......Therapeutic monoclonal antibodies (mAbs) are mainly produced by heterogonous expression in Chinese hamster ovary (CHO) cells. The glycosylation profile of the mAbs has major impact on the efficacy and safety of the drug and is therefore an important parameter to control during production...... heterogeneity and glycosylation patterns of IgG. None of the eight feed additives caused statistically significant changes to cell growth or IgG productivity, compared to controls. However, the addition of 20 mM galactose did result in a reproducible increase of galactosylated IgG from 14% to 25%. On the other...

  17. Inactivation of GDP-fucose transporter gene (Slc35c1) in CHO cells by ZFNs, TALENs and CRISPR-Cas9 for production of fucose-free antibodies.

    Science.gov (United States)

    Chan, Kah Fai; Shahreel, Wahyu; Wan, Corrine; Teo, Gavin; Hayati, Noor; Tay, Shi Jie; Tong, Wen Han; Yang, Yuansheng; Rudd, Pauline M; Zhang, Peiqing; Song, Zhiwei

    2016-03-01

    Removal of core fucose from N-glycans attached to human IgG1 significantly enhances its affinity for the receptor FcγRIII and thereby dramatically improves its antibody-dependent cellular cytotoxicity activity. While previous works have shown that inactivation of fucosyltransferase 8 results in mutants capable of producing fucose-free antibodies, we report here the use of genome editing techniques, namely ZFNs, TALENs and the CRISPR-Cas9, to inactivate the GDP-fucose transporter (SLC35C1) in Chinese hamster ovary (CHO) cells. A FACS approach coupled with a fucose-specific lectin was developed to rapidly isolate SLC35C1-deficient cells. Mass spectrometry analysis showed that both EPO-Fc produced in mutants arising from CHO-K1 and anti-Her2 antibody produced in mutants arising from a pre-existing antibody-producing CHO-HER line lacked core fucose. Lack of functional SLC35C1 in these cells does not affect cell growth or antibody productivity. Our data demonstrate that inactivating Slc35c1 gene represents an alternative approach to generate CHO cells for production of fucose-free antibodies.

  18. DNA and chromosome breaks induced by {sup 123}I-estrogen in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, J.L. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology]|[Univ. of Chicago, IL (United States). Dept. of Radiation and Cellular Oncology; Mustafi, R.; Hughes, A.; DeSombre, E.R. [Univ. of Chicago, IL (United States)

    1997-07-01

    The effects of the Auger electron-emitting isotope I-123, covalently bound to estrogen, on DNA single- and double-strand breakage and on chromosome breakage was determined in estrogen positive Chinese hamster ovary (CHO-ER) cells. Exposure to the {sup 123}I-estrogen induced both single- and double-strand breaks with a ratio of single- to double-strand breaks of 2.2. The corresponding ratio with {sup 60}Co gamma rays was 15.6. The dose-response was biphasic suggesting that either receptor sites are saturated at high does, or that there is a nonrandom distribution of breaks induced by the {sup 123}I-estrogen. The {sup 123}I-estrogen treatment induced chromosome aberrations with an efficiency of about 1 aberration for each 1,000 disintegrations per cell. This corresponds to the mean lethal dose of {sup 123}I-estrogen for these cells suggesting that the lethal event induced by the Auger electron emitter bound to estrogen is a chromosome aberration. Most of the chromosome-type aberrations were dicentrics and rings, suggesting that {sup 123}I-estrogen-induced chromosome breaks are rejoined. The F-ratio, the ratio of dicentrics to centric rings, was 5.8 {plus_minus} 1.7, which is similar to that seen with high LET radiations. Their results suggest that I-123 bound to estrogen is an efficient clastogenic agent, that the cytotoxic damage produced by I-123 bound to estrogen is very like high LET-induced damage, and the I-123 in the estrogen-receptor-DNA complex is probably in close proximity to the sugar-phosphate backbone of the DNA.

  19. DNA double-strand break induction in Ku80-deficient CHO cells following Boron Neutron Capture Reaction

    Directory of Open Access Journals (Sweden)

    Masunaga Shinichiro

    2011-09-01

    Full Text Available Abstract Background Boron neutron capture reaction (BNCR is based on irradiation of tumors after accumulation of boron compound. 10B captures neutrons and produces an alpha (4He particle and a recoiled lithium nucleus (7Li. These particles have the characteristics of high linear energy transfer (LET radiation and have marked biological effects. The purpose of this study is to verify that BNCR will increase cell killing and slow disappearance of repair protein-related foci to a greater extent in DNA repair-deficient cells than in wild-type cells. Methods Chinese hamster ovary (CHO-K1 cells and a DNA double-strand break (DSB repair deficient mutant derivative, xrs-5 (Ku80 deficient CHO mutant cells, were irradiated by thermal neutrons. The quantity of DNA-DSBs following BNCR was evaluated by measuring the phosphorylation of histone protein H2AX (gamma-H2AX and 53BP1 foci using immunofluorescence intensity. Results Two hours after neutron irradiation, the number of gamma-H2AX and 53BP1 foci in the CHO-K1 cells was decreased to 36.5-42.8% of the levels seen 30 min after irradiation. In contrast, two hours after irradiation, foci levels in the xrs-5 cells were 58.4-69.5% of those observed 30 min after irradiation. The number of gamma-H2AX foci in xrs-5 cells at 60-120 min after BNCT correlated with the cell killing effect of BNCR. However, in CHO-K1 cells, the RBE (relative biological effectiveness estimated by the number of foci following BNCR was increased depending on the repair time and was not always correlated with the RBE of cytotoxicity. Conclusion Mutant xrs-5 cells show extreme sensitivity to ionizing radiation, because xrs-5 cells lack functional Ku-protein. Our results suggest that the DNA-DSBs induced by BNCR were not well repaired in the Ku80 deficient cells. The RBE following BNCR of radio-sensitive mutant cells was not increased but was lower than that of radio-resistant cells. These results suggest that gamma-ray resistant cells have

  20. Propranolol induced chromosomal aberrations in Chinese hamster ovary cell line

    Directory of Open Access Journals (Sweden)

    Mozhgan Sedigh-Ardekani

    2013-03-01

    Full Text Available Propranolol (PL, a non-selective beta-blocker, is a cardiovascular drug widely used to treat hypertension. The present study was concerned with assessing the cytogenetic effects of this drug on Chinese hamster ovary (CHO cell line. MTT assay was then carried out to determine the cytotoxicity index (IC50 of the drug. The IC50 value of PL was 0.43±0.02 mM. To investigate the clastogenic effects of the drug, chromatid and chromosome breaks and polyploidy in metaphases were analyzed. CHO cells were exposed to different concentrations of the drug (0.1, 0.2, 0.3, 0.4 mM for 24 hours. Considering that PL has liver metabolism, experiments were carried out in the presence and absence of the metabolic activation system (S9 mix. Mitomycin-C and sodium arsenite were used as positive controls. It was observed that in cells treated with different PL concentrations as 0.1, 0.2 and 0.3 mM, the frequency of chromatid and chromosome breaks as well as polyploidy increased when compared with untreated CHO cells. The addition of S9 mix significantly decreased the chromatid breaks, chromosome breaks and polyploidy compared to the treatment of PL alone. It is concluded that, PL causes chromatid and chromosome aberrations in CHO cell line and the metabolic activation system (S9 mix, playing an important role in drug cytotoxicity reduction.

  1. Removal of endogenous retrovirus-like particles from CHO-cell derived products using Q sepharose fast flow chromatography.

    Science.gov (United States)

    Strauss, Daniel M; Lute, Scott; Brorson, Kurt; Blank, Gregory S; Chen, Qi; Yang, Bin

    2009-01-01

    Retrovirus-like particles (RVLPs) that are expressed during the production of monoclonal antibodies in Chinese hamster ovary (CHO) cell cultures must be removed during product recovery. Anion exchange chromatography (AEX) performed in product flow-through mode, a common component in the purification of monoclonal antibodies, has been shown to provide robust removal of a related retrovirus model, but it's ability to remove the actual RVLP impurities has not been directly investigated. We have determined the ability of a typical Q sepharose process to remove actual CHO RVLP impurities. Using small scale experiments with three model antibodies, we observe that this AEX process is capable of effectively removing both in-process and spiked RVLPs from different feedstocks containing different mAb products. In addition, we show that this AEX process also achieves a similarly high degree of RVLP removal during large scale manufacturing operations.

  2. Development of a new bioprocess scheme using frozen seed train intermediates to initiate CHO cell culture manufacturing campaigns.

    Science.gov (United States)

    Seth, Gargi; Hamilton, Robert W; Stapp, Thomas R; Zheng, Lisa; Meier, Angela; Petty, Krista; Leung, Stephenie; Chary, Srikanth

    2013-05-01

    Agility to schedule and execute cell culture manufacturing campaigns quickly in a multi-product facility will play a key role in meeting the growing demand for therapeutic proteins. In an effort to shorten campaign timelines, maximize plant flexibility and resource utilization, we investigated the initiation of cell culture manufacturing campaigns using CHO cells cryopreserved in large volume bags in place of the seed train process flows that are conventionally used in cell culture manufacturing. This approach, termed FASTEC (Frozen Accelerated Seed Train for Execution of a Campaign), involves cultivating cells to high density in a perfusion bioreactor, and cryopreserving cells in multiple disposable bags. Each run for a manufacturing campaign would then come from a thaw of one or more of these cryopreserved bags. This article reviews the development and optimization of individual steps of the FASTEC bioprocess scheme: scaling up cells to greater than 70 × 10(6) cells/mL and freezing in bags with an optimized controlled rate freezing protocol and using a customized rack configuration. Flow cytometry analysis was also employed to understand the recovery of CHO cells following cryopreservation. Extensive development data were gathered to ensure that the quantity and quality of the drug manufactured using the FASTEC bioprocess scheme was acceptable compared to the conventional seed train process flow. The result of offering comparable manufacturing options offers flexibility to the cell culture manufacturing network.

  3. Enhancement of recombinant human EPO production and glycosylation in serum-free suspension culture of CHO cells through expression and supplementation of 30Kc19.

    Science.gov (United States)

    Park, Ju Hyun; Wang, Zesong; Jeong, Hee-Jin; Park, Hee Ho; Kim, Byung-Gee; Tan, Wen-Song; Choi, Shin Sik; Park, Tai Hyun

    2012-11-01

    We previously reported that the expression of Bombyx mori 30Kc19 gene in CHO cells significantly improved both the production and sialylation of recombinant human EPO (rHuEPO) in adhesion culture mode. In this study, the effects of 30Kc19 expression and supplementation of 30Kc19 recombinant protein on the productivity and glycosylation pattern of rHuEPO were investigated in the serum-free suspension culture mode. Especially, glycosylation pattern was examined in detail using a quantitative MALDI-TOF MS method. The expression of 30Kc19 increased the EPO production by 2.5-folds and the host cells produced rHuEPO with more complex glycan structures and a larger content of sialic acid and fucose. The glycan structures of rHuEPO in the 30Kc19-expressing cell consisted of bi-, tri-, tetra-, and penta-antennary branching (35, 18, 33, and 14 %, respectively), while the control cells produced predominantly bi-antennary branching (70 %). About 53 % of the glycans from rHuEPO in the 30Kc19-expressing cell was terminally sialylated, while no obvious sialylated glycan was found in the control cells. The percentage of fucosylated glycans from the 30Kc19-expressing cell culture was 77 %, whereas only 61 % of the glycans from the control cell were fucosylated glycans. We also examined whether these effects were observed when the recombinant 30Kc19 protein produced from Escherichia coli was supplemented into the culture medium for CHO cells. In the control cell line without the 30Kc19 gene, EPO production increased by 41.6 % after the addition of 0.2 mg/mL of the recombinant 30Kc19 protein to the culture medium. By the Western blot analysis after two-dimensional electrophoresis (2-DE) of isoforms of EPO, we confirmed that 30Kc19 enhanced the sialylation of EPO glycans. These results demonstrated that both 30Kc19 gene expression and the recombinant 30Kc19 protein addition enhanced rHuEPO productivity and glycosylation in suspension culture. In conclusion, the utilization of

  4. Origin and evolution of binucleated cells and binucleated cells with micronuclei in cisplatin-treated CHO cultures.

    Science.gov (United States)

    Rodilla, V

    1993-08-01

    It has recently been described that cisplatin is an agent able to induce binucleated cells (BC) in cultured CHO cells. Both the origin and the significance of those cells within a population are unknown although several hypothesis have been suggested such as blocking of cytokinesis or cell fusion. Using interval photography we have found that at least two mechanisms are involved in the production of BC. These cells can arise in a culture as a result of an incomplete process of cell division, i.e. karyokinesis with incomplete cytokinesis or as a result of the mitotic division of a pre-existent BC. The mitotic division of a BC can give rise to different types of daughter cells. These BC sometimes enter mitosis but fail to divide and as a consequence they remain BC. When the process of division is successful (in the vast majority of cases), the results that have been found are either two mononucleated cells or one mononucleated and one binucleated cell. The possible implications and significance of BC and BC with micronuclei in a given population are discussed.

  5. Design of serum-free medium for suspension culture of CHO cells on the basis of general commercial media.

    Science.gov (United States)

    Miki, Hideo; Takagi, Mutsumi

    2015-08-01

    The design of serum-free media for suspension culture of genetically engineered Chinese hamster ovary (CHO) cells using general commercial media as a basis was investigated. Subcultivation using a commercial serum-free medium containing insulin-like growth factor (IGF)-1 with or without FCS necessitated additives other than IGF-1 to compensate for the lack of FCS and improve cell growth. Suspension culture with media containing several combinations of growth factors suggested the effectiveness of addition of both IGF-1 and the lipid signaling molecule lysophosphatidic acid (LPA) for promoting cell growth. Subcultivation of CHO cells in suspension culture using the commercial serum-free medium EX-CELL™302, which contained an IGF-1 analog, supplemented with LPA resulted in gradually increasing specific growth rate comparable to the serum-containing medium and in almost the same high antibody production regardless of the number of generations. The culture with EX-CELL™302 supplemented with LPA in a jar fermentor with pH control at 6.9 showed an apparently higher cell growth rate than the cultures without pH control and with pH control at 6.8. The cell growth in the medium supplemented with aurintricarboxylic acid (ATA), which was much cheaper than IGF-1, in combination with LPA was synergistically promoted similarly to that in the medium supplemented with IGF-1 and LPA. In conclusion, the serum-free medium designed on the basis of general commercial media could support the growth of CHO cells and antibody production comparable to serum-containing medium in suspension culture. Moreover, the possibility of cost reduction by the substitution of IGF-1 with ATA was also shown.

  6. Induction of 8-hydroxy-2'-deoxyguanosine in CHO-K1 cells exposed to phenyl-hydroquinone, a metabolite of ortho-phenylphenol.

    Science.gov (United States)

    Nakagawa, Y; Tayama, S

    1996-03-29

    The induction of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an index of oxidative DNA modification, was investigated in CHO-K1 cells exposed to phenyl-hydroquinone (PHQ), a major metabolite of ortho-phenylphenol (OPP), an antimicrobial. Addition of PHQ at a concentration of 50 microM to CHO cell suspensions (10(6) cells/ml) induced slight elevation of intracellular 8-OHdG levels. Pretreatment of CHO cells with 3-amino-1,2,4-triazole (AT, 20 mM) enhanced PHQ-induced 8-OHdG formation which was accompanied by cell death. Pretreatment of CHO-K1 cells with AT (20 mM) and deferoxamine (DeFe, 20 mM) inhibited the formation of 8-OHdG as well as cell death caused by PHQ. Neither AT nor DeFe affected cell viability or the formation of 8-OHdG in untreated CHO cells during the incubation period. The loss of cellular glutathione induced by the addition of PHQ alone was enhanced by the pretreatment of CHO cells with AT or AT plus DeFe. When PHQ was added to AT-pretreated cell suspensions, the concentration of PHQ decreased with time. This decrease was accompanied by the formation of phenyl-benzoquinone (PBQ). These results suggest that the reactive oxygen species derived from autoxidation of PHQ which converts to PBQ via phenyl-semiquinone elicit DNA damage in CHO cells, especially when the activity of cellular catalase is inhibited.

  7. RCA-I-resistant CHO mutant cells have dysfunctional GnT I and expression of normal GnT I in these mutants enhances sialylation of recombinant erythropoietin.

    Science.gov (United States)

    Goh, John S Y; Zhang, Peiqing; Chan, Kah Fai; Lee, May May; Lim, Sing Fee; Song, Zhiwei

    2010-07-01

    A large number of CHO glycosylation mutants were isolated by Ricinus communis agglutinin-I (RCA-I). Complementation tests revealed that all these mutant lines possessed a dysfunctional N-acetylglucosaminyltransferase I (GnT I) gene. Sequencing analyses on the GnT I cDNAs isolated from 16 mutant lines led to the identification of nine different single base pair mutations. Some mutations result in a premature stop codon whereas others cause a single amino acid substitution in the GnT I protein. Interestingly, expression of the normal GnT I cDNA in mutant cells resulted in enhanced sialylation of N-glycans. The sialylation of recombinant erythropoietin (EPO) produced in mutant cells that were co-transfected with GnT I was enhanced compared to that of EPO produced in wild type CHO cells. The enhanced sialylation of EPO produced by JW152 cells in the presence of GnT I over CHO-K1 cells is a result of increased sialylated glycan structures with higher antennary branching. These findings represent a new strategy that may be utilized by the biotechnology industry to produce highly sialylated therapeutic glycoproteins.

  8. Cytotoxicity Evaluation of Anatase and Rutile TiO2 Thin Films on CHO-K1 Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Blanca Cervantes

    2016-07-01

    Full Text Available Cytotoxicity of titanium dioxide (TiO2 thin films on Chinese hamster ovary (CHO-K1 cells was evaluated after 24, 48 and 72 h of culture. The TiO2 thin films were deposited using direct current magnetron sputtering. These films were post-deposition annealed at different temperatures (300, 500 and 800 °C toward the anatase to rutile phase transformation. The root-mean-square (RMS surface roughness of TiO2 films went from 2.8 to 8.08 nm when the annealing temperature was increased from 300 to 800 °C. Field emission scanning electron microscopy (FESEM results showed that the TiO2 films’ thickness values fell within the nanometer range (290–310 nm. Based on the results of the tetrazolium dye and trypan blue assays, we found that TiO2 thin films showed no cytotoxicity after the aforementioned culture times at which cell viability was greater than 98%. Independently of the annealing temperature of the TiO2 thin films, the number of CHO-K1 cells on the control substrate and on all TiO2 thin films was greater after 48 or 72 h than it was after 24 h; the highest cell survival rate was observed in TiO2 films annealed at 800 °C. These results indicate that TiO2 thin films do not affect mitochondrial function and proliferation of CHO-K1 cells, and back up the use of TiO2 thin films in biomedical science.

  9. Protective effect of propolis on radiation-induced chromosomal damage on Chinese hamster ovary cells (CHO-K1)

    Energy Technology Data Exchange (ETDEWEB)

    Spigoti, Geyza; Bartolini, Paolo; Okazaki, Kayo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: kokazaki@ipen.br; Tsutsumi, Shiguetoshi [Amazon Food Ltd., Tokyo (Japan)], e-mail: fwip5138@mb.infoweb.ne.jp

    2009-07-01

    In the last years, particular interest has been given to investigations concerning natural, effective and nontoxic compounds with radioprotective capacity in concert with increasing utilization of different types of ionizing radiation for various applications. Among them, propolis, a resinous mixture of substances collected by honey bees (Apis mellifera) has been considered promising since it presents several advantageous characteristics, i.e., antiinflammatory, anticarcinogenic, antimicrobial and free radical scavenging action. It is, therefore, a direct antioxidant that protects cells and organisms from the adverse effects of ionizing radiation. These relevant biological activities are mainly mediated by the flavonoids, present at relatively high concentrations in the propolis. Considering that the chemical composition and, consequently, the biological activity of propolis is variable according to the environmental plant ecology, the present study was conducted in order to evaluate the radioprotective capacity of Brazilian propolis, collected in the State of Rio Grande do Sul, against genotoxic damages induced by {sup 60}Co {gamma}-radiation in Chinese hamster ovary cells (CHO-K1). for this purpose, micronucleus induction was analyzed concerning irreparable damage, specifically related to DNA double-strand breaks, that are potentially carcinogenic. CHO-K1 cells were submitted to different concentrations of propolis (3 - 33 {mu}g/ml), 1 h before irradiation, with 1 Gy of {gamma} radiation (0.722 Gy/min). The data obtained showed a decreasing tendency in the quantity of radioinduced damage on cells previously treated with propolis. The radioprotective effect was more prominent at higher propolis concentration. The treatment with propolis alone did not induce genotoxic effects on CHO-K1 cells. Beside that, the treatment with propolis, associated or not with radiation, did not influence the kinetics of cellular proliferation. (author)

  10. Dynamics of immature mAb glycoform secretion during CHO cell culture

    DEFF Research Database (Denmark)

    Jimenez del Val, Ioscani; Fan, Yuzhou; Weilguny, Dietmar

    2016-01-01

    required to minimise mAb glycoform variability. Our results suggest that the availability of glycosylation machinery relative to cellular secretory capacity may play a crucial role in mAb glycosylation. In the future, the modelling framework presented here may aid in selecting and engineering cell lines...

  11. THERMAL RADIOSENSITIZATION IN HEAT-SENSITIVE AND RADIATION-SENSITIVE MUTANTS OF CHO CELLS

    NARCIS (Netherlands)

    KAMPINGA, HH; KANON, B; KONINGS, AWT; STACKHOUSE, MA; BEDFORD, JS

    1993-01-01

    Recently, it has been hypothesized (Iliakis and Seaner 1990) that DNA double-strand break (dsb) repair proficiency is a prerequisite for heat radiosensitization on the basis of the finding that the radiosensitive and dsb-repair-deficient mutant xrs-5 cell line shows no significant heat-induced radio

  12. Insertion of core CpG island element into human CMV promoter for enhancing recombinant protein expression stability in CHO cells.

    Science.gov (United States)

    Mariati; Yeo, Jessna H M; Koh, Esther Y C; Ho, Steven C L; Yang, Yuansheng

    2014-01-01

    The human cytomegalovirus promoter (hCMV) is susceptible to gene silencing in CHO cells, most likely due to epigenetic events, such as DNA methylation and histone modifications. The core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene has been shown to prevent DNA methylation. A set of modified hCMV promoters was developed by inserting one or two copies of IE in either forward or reverse orientations either upstream of the hCMV enhancer, between the enhancer and core promoter (CP), or downstream of the CP. The modified hCMV with one copy of IE inserted between the enhancer and core promoter in reverse orientation (MR1) was most effective at enhancing expression stability without compromising expression level when compared with the wild-type (WT) hCMV. A third of 18 EGFP expressing clones generated using MR1 retained 70% of their starting expression level after 8 weeks of culture in the absence of selection pressure, while none of 18 WT hCMV generated clones had expression above 50%. MR1 also improved antibody expression stability of methotrexate (MTX) amplified CHO cell lines. Stably transfected pools generated using MR1 maintained 62% of their original monoclonal antibody titer after 8 weeks of culture in the absence of MTX, compared to only 37% for WT hCMV pools. Low levels of CpG methylation within both WT hCMV and MR1 were observed in all the analyzed cell lines and the methylation levels did not correlate to the expression stability, suggesting IE enhances expression stability by other mechanisms other than preventing methylation.

  13. Integrated cell and process engineering for improved transient production of a "difficult-to-express" fusion protein by CHO cells.

    Science.gov (United States)

    Johari, Yusuf B; Estes, Scott D; Alves, Christina S; Sinacore, Marty S; James, David C

    2015-12-01

    Based on an optimized electroporation protocol, we designed a rapid, milliliter-scale diagnostic transient production assay to identify limitations in the ability of Chinese hamster ovary (CHO) cells to produce a model "difficult-to-express" homodimeric Fc-fusion protein, Sp35Fc, that exhibited very low volumetric titer and intracellular formation of disulfide-bonded oligomeric aggregates post-transfection. As expression of Sp35Fc induced an unfolded protein response in transfected host cells, we utilized the transient assay to compare, in parallel, multiple functionally diverse strategies to engineer intracellular processing of Sp35Fc in order to increase production and reduce aggregation as two discrete design objectives. Specifically, we compared the effect of (i) co-expression of ER-resident molecular chaperones (BiP, PDI, CypB) or active forms of UPR transactivators (ATF6c, XBP1s) at varying recombinant gene load, (ii) addition of small molecules known to act as chemical chaperones (PBA, DMSO, glycerol, betaine, TMAO) or modulate UPR signaling (PERK inhibitor GSK2606414) at varying concentration, (iii) a reduction in culture temperature to 32°C. Using this information, we designed a biphasic, Sp35Fc-specific transient manufacturing process mediated by lipofection that utilized CypB co-expression at an optimal Sp35Fc:CypB gene ratio of 5:1 to initially maximize transfected cell proliferation, followed by addition of a combination of PBA (0.5 mM) and glycerol (1% v/v) at the onset of stationary phase to maximize cell specific production and eliminate Sp35Fc aggregation. Using this optimal, engineered process transient Sp35Fc production was significantly increased sixfold over a 12 day production process with no evidence of disulfide-bonded aggregates. Finally, transient production in clonally derived sub-populations (derived from parental CHO host) screened for a heritably improved capability to produce Sp35Fc was also significantly improved by the optimized

  14. Storage of cell lines.

    Science.gov (United States)

    Parker, Katharine A

    2011-01-01

    The successful storage of cell lines depends upon many factors, including the condition of the cells to be frozen and the experience of the operator. Attempting to freeze down unhealthy, contaminated or poorly labelled cells can have huge implications for a research laboratory. This chapter outlines the importance of good record keeping, vigilant monitoring, aseptic technique, and high-quality reagents in the successful storage and downstream propagation of cell lines.

  15. Fractionation of yeast extract by nanofiltration process to assess key compounds involved in CHO cell culture improvement.

    Science.gov (United States)

    Mosser, Mathilde; Kapel, Romain; Chevalot, Isabelle; Olmos, Eric; Marc, Ivan; Marc, Annie; Oriol, Eric

    2015-01-01

    Yeast extract (YE) is known to greatly enhance mammalian cell culture performances, but its undefined composition decreases process reliability. Accordingly, in the present study, the nature of YE compounds involved in the improvement of recombinant CHO cell growth and IgG production was investigated. First, the benefits of YE were verified, revealing that it increased maximal concentrations of viable cells and IgG up to 73 and 60%, respectively compared to a reference culture. Then, the analyses of YE composition highlighted the presence of molecules such as amino acids, vitamins, salts, nucleobase, and glucose that were contained in reference medium, while others including peptides, trehalose, polysaccharides, and nucleic acids were not. Consequently, YE was fractionated by a nanofiltration process to deeper evaluate its effects on CHO cell cultures. The YE molecules already contained in reference medium were mainly isolated in the permeate fraction together with trehalose and short peptides, while other molecules were concentrated in the retentate. Permeate, which was free of macromolecules, exhibited a similar positive effect than raw YE on maximal concentrations. Additional studies on cell energetic metabolism underlined that dipeptides and tripeptides in permeate were used as an efficient source of nitrogenous substrates.

  16. Increased repair of {gamma}-induced DNA double-strand breaks at lower dose-rate in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, D.; Hindo, J.; Averbeck, D. [Centre Universitaire d' Orsay, Inst. Curie-Section de Recherche, Orsay CEDEX (France)]. E-mail: dietrich.averbeck@curie.u-psud.fr

    2004-02-01

    DNA double-strand breaks (DSBs) are highly cell damaging. We asked whether for a given dose a longer irradiation time would be advantageous for the repair of DSBs. Varying the {gamma}-irradiation dose and its delivery time (0.05 Gy/min low dose-rate (LDR) compared with 3.5 Gy/min high dose-rate), confluent Chinese hamster ovary cells (CHO-K1) and Ku80 mutant cells (xrs-6) deficient in nonhomologous end-joining (NHEJ) were irradiated in agarose plugs at room temperature using a cesium-137 {gamma}-ray source. We used pulsed-field gel electrophoresis (PFGE) to measure DSBs in terms of the fraction of activity released (FAR). At LDR, one third of DSBs were repaired in CHO-K1 but not in xrs-6 cells, indicating the involvement of NHEJ in the repair of {gamma}-induced DSBs at a prolonged irradiation incubation time. To improve DSB measurements, we introduced in our PFGE protocol an antioxidant at the cell lysis step, thus avoiding free-radical side reactions on DNA and spurious DSBs. Addition of the metal chelator deferoxamine (DFO) decreased more efficiently the basal DSB level than did reduced glutathione (GSH), showing that measuring DSBs in the absence of DFO reduces precision and underestimates the role of NHEJ in the dose-rate effect on DSB yield. (author)

  17. Generation of high-producing cell lines by overexpression of cell division cycle 25 homolog A in Chinese hamster ovary cells.

    Science.gov (United States)

    Lee, Kyoung Ho; Tsutsui, Tomomi; Honda, Kohsuke; Asano, Ryutaro; Kumagai, Izumi; Ohtake, Hisao; Omasa, Takeshi

    2013-12-01

    To improve the efficiency of conventional gene amplification systems, the effect of cell cycle modification during the gene amplification process on IgG production was investigated in Chinese hamster ovary (CHO) cells. The full-length cDNA of CHO cell division cycle 25 homolog A (Cdc25A) was introduced into CHO DG44 cells and the effects of CDC25A overexpression on the cell cycle, transgene copy number and IgG productivity were examined. Both wild-type and mutated CDC25A-overexpressing CHO cells showed a rapid increase in transgene copy number compared with mock cells during the gene amplification process, in both cell pools and individual clones. High-producing clones were obtained with high frequency in CDC25A-overexpressing cell pools. The specific production rate of the isolated clone CHO SD-S23 was up to 2.9-fold higher than that of mock cells in the presence of 250 nM methotrexate (MTX). Cell cycle analysis revealed that the G2 to M phase transition rate was increased ∼1.5-fold in CDC25A-overexpressing CHO cells under MTX treatment. Our results show the improvement of conventional gene amplification systems via cell cycle engineering at an early stage of cell line development.

  18. Determinants of intrinsic radiosensitivity of mammalian cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Radford, I.R. [Peter MacCallum Cancer Institute, East Melbourne, VIC (Australia). Research Division

    1998-12-31

    Differences in the radiosensitivity of normal and cancerous cells could arise in various ways. Although there is no compelling data to support the view, the currently prevailing opinion is that differences in radiosensitivity are related to differences in some aspect of enzymatic DNA repair. A test of the importance of possible differences in enzymatic DNA repair in determining relative radiosensitivity would be to compare lethality in cells containing equivalent numbers of DNA lesions. Six cell lines were used in these studies: two Chinese hamster (CHO and V79) and a monkey (Vero) fibroblast-like line, a mouse melanoma line (B16-F1), and a rat (RUC-2) and a human (SQ-20B) carcinoma line. This group of cell lines displays a wide range of sensitivities to external beam low-LET radiation, ranging from the relatively radiosensitive B16-F1 and Vero lines through to the highly radioresistant RUC-2 line. However, it is important to note that none of the lines has a demonstrated defect in enzymatic DNA repair and that all appear to die by necrosis following a lethal radiation insult. Despite having significantly different radiosensitivities, CHO and V79 cells showed comparable responses to DNA-associated {sup 125}I-decays with D{sub o} values of around 65. More surprisingly, the radiosensitive B16-F1 line and the radioresistant RUC-2 line both had responses with D{sub o} values of around 133 {sup 125}I-decays. The factor of two difference between the D{sub o} values for these two pairs of cell lines is probably attributable to CHO and V79 cells being pseudo-diploid whereas B 16-F1 and RUC2 appear to have derived from tetraploid cells. The generality of the above result, for DNA lesions of different quality, was tested by comparing the sensitivities of CHO and V79 cells to DNA-associated {sup 3}H-decays. Again, consistent with the {sup 125}I-decay data, there was no significant difference in the D{sub o} values for these lines. Our {sup 3}H- and {sup 125}I-decay data are

  19. The systematic study of the electroporation and electrofusion of B16-F1 and CHO cells in isotonic and hypotonic buffer.

    Science.gov (United States)

    Usaj, Marko; Kanduser, Masa

    2012-09-01

    The fusogenic state of the cell membrane can be induced by external electric field. When two fusogenic membranes are in close contact, cell fusion takes place. An appropriate hypotonic treatment of cells before the application of electric pulses significantly improves electrofusion efficiency. How hypotonic treatment improves electrofusion is still not known in detail. Our results indicate that at given induced transmembrane potential electroporation was not affected by buffer osmolarity. In contrast to electroporation, cells' response to hypotonic treatment significantly affects their electrofusion. High fusion yield was observed when B16-F1 cells were used; this cell line in hypotonic buffer resulted in 41 ± 9 % yield, while in isotonic buffer 32 ± 11 % yield was observed. Based on our knowledge, these fusion yields determined in situ by dual-color fluorescence microscopy are among the highest in electrofusion research field. The use of hypotonic buffer was more crucial for electrofusion of CHO cells; the fusion yield increased from below 1 % in isotonic buffer to 10 ± 4 % in hypotonic buffer. Since the same degree of cell permeabilization was achieved in both buffers, these results indicate that hypotonic treatment significantly improves fusion yield. The effect could be attributed to improved physical contact of cell membranes or to enhanced fusogenic state of the cell membrane itself.

  20. DNA-DSB in CHO-K1 cells induced by heavy-ions: Break rejoining and residual damage (GSI)

    Science.gov (United States)

    Taucher-Scholz, G.; Heilmann, J.; Becher, G.; Kraft, G.

    1994-01-01

    DNA double strand breaks (DSB's) are the critical lesions involved in cellular effects of ionizing radiation. Therefore, the evaluation of DSB induction in mammalian cells after heavy ion irradiation is an essential task for the assessment of high-LET radiation risk in space. Of particular interest has been the question of how the biological efficiency for the cellular inactivation endpoint relates to the initial lesions (DSBs) at varying LETs. For cell killing, an increased Relative Biological Efficiency (RBE) has been determined for highLET radiation around 100-200 keV/mu m. At higher LET, the RBE's decrease again to values below one for the very heavy particles. At GSI, DSB-induction was measured in CHO-K1 cells following irradiation with accelerated particles covering a wide LET range. The electrophoretic elution of fragmented DNA out of agarose plugs in a constant electrical field was applied for the detection of DSB's. The fraction of DNA retained was determined considering the relative intensities of ethidium bromide fluorescence in the well and in the gel lane. Dose-effect curves were established, from which the RBE for DSB induction was calculated at a fraction of 0.7 of DNA retained In summary, these rejoining studies are in line with an enhanced severity of the DNA DSB's at higher LET's, resulting in a decreased repairability of the induced lesions. However, no information concerning the fidelity of strand breaks rejoining is provided in these studies. To assess correct rejoining of DNA fragments an experimental system involving individual DNA hybridization bands has been set up. In preliminary experiments Sal I generated DNA fragments of 0.9 Mbp were irradiated with xrays and incubated for repair However, restitution of the original signals was not observed, probably due to the high radiation dose necessary for breakage of a fragment of this size. A banding pattern with NotI hybridization signals in a higher MW range (3Mbp) has been obtained by varying

  1. Multi-omic profiling of EPO-producing CHO cell panel reveals metabolic adaptation to heterologous protein production

    DEFF Research Database (Denmark)

    Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

    expressed genes related to secretory protein processing. However, when inspecting the gene expression landscape of the aminoacid catabolism, we observed an apparent adaptation in favor of EPO production. That is, we discovered that the gene expression levels of amino acid catabolic genes had adapted...... to preserve the most abundant aminoacids in EPO in the high producing clone relative to the low producing clone. Based on these data, we speculate that the amino acid metabolism in CHO cells may undergo adaptation in favor of heterologous protein production during long-term cultivation....

  2. Antioxidant and DNA Repair Stimulating Effect of Extracts from Transformed and Normal Roots of Rhaponticum carthamoides against Induced Oxidative Stress and DNA Damage in CHO Cells

    Science.gov (United States)

    Skała, Ewa; Sitarek, Przemysław; Różalski, Marek; Krajewska, Urszula; Szemraj, Janusz; Wysokińska, Halina; Śliwiński, Tomasz

    2016-01-01

    Rhaponticum carthamoides has a long tradition of use in Siberian folk medicine. The roots and rhizomes of this species are used in various dietary supplements or nutraceutical preparations to increase energy level or eliminate physical weakness. This is the first report to reveal the protective and DNA repair stimulating abilities of R. carthamoides root extracts in Chinese hamster ovary (CHO) cells exposed to an oxidative agent. Both transformed root extract (TR extract) and extract of soil-grown plant roots (NR extract) may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, but CHO cells stimulated with extract from the transformed roots demonstrated significantly stronger properties than cells treated with the soil-grown plant root extract. These differences in biological activity may be attributed to the differences in the content of phenolic compounds in these root extracts. Preincubation of the CHO cells with TR and NR extracts showed an increase in gene expression and protein levels of catalase (CAT) and superoxide dismutase (SOD2). R. carthamoides may possess antioxidant properties that protect CHO cells against oxidative stress. PMID:27034736

  3. Antioxidant and DNA Repair Stimulating Effect of Extracts from Transformed and Normal Roots of Rhaponticum carthamoides against Induced Oxidative Stress and DNA Damage in CHO Cells

    Directory of Open Access Journals (Sweden)

    Ewa Skała

    2016-01-01

    Full Text Available Rhaponticum carthamoides has a long tradition of use in Siberian folk medicine. The roots and rhizomes of this species are used in various dietary supplements or nutraceutical preparations to increase energy level or eliminate physical weakness. This is the first report to reveal the protective and DNA repair stimulating abilities of R. carthamoides root extracts in Chinese hamster ovary (CHO cells exposed to an oxidative agent. Both transformed root extract (TR extract and extract of soil-grown plant roots (NR extract may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, but CHO cells stimulated with extract from the transformed roots demonstrated significantly stronger properties than cells treated with the soil-grown plant root extract. These differences in biological activity may be attributed to the differences in the content of phenolic compounds in these root extracts. Preincubation of the CHO cells with TR and NR extracts showed an increase in gene expression and protein levels of catalase (CAT and superoxide dismutase (SOD2. R. carthamoides may possess antioxidant properties that protect CHO cells against oxidative stress.

  4. Optimization of heavy chain and light chain signal peptides for high level expression of therapeutic antibodies in CHO cells.

    Directory of Open Access Journals (Sweden)

    Ryan Haryadi

    Full Text Available Translocation of a nascent protein from the cytosol into the ER mediated by its signal peptide is a critical step in protein secretion. The aim of this work was to develop a platform technology to optimize the signal peptides for high level production of therapeutic antibodies in CHO cells. A database of signal peptides from a large number of human immunoglobulin (Ig heavy chain (HC and kappa light chain (LC was generated. Most of the HC signal peptides contain 19 amino acids which can be divided into three domains and the LC signal peptides contain 22 amino acids. The signal peptides were then clustered according to sequence similarity. Based on the clustering, 8 HC and 2 LC signal peptides were analyzed for their impacts on the production of 5-top selling antibody therapeutics, namely, Herceptin, Avastin, Remicade, Rituxan, and Humira. The best HC and LC signal peptides for producing these 5 antibodies were identified. The optimized signal peptides for Rituxan is 2-fold better compared to its native signal peptides which are available in the public database. Substitution of a single amino acid in the optimized HC signal peptide for Avastin reduced its production significantly. Mass spectrometry analyses revealed that all optimized signal peptides are accurately removed in the mature antibodies. The results presented in this report are particularly important for the production of these 5 antibodies as biosimilar drugs. They also have the potential to be the best signal peptides for the production of new antibodies in CHO cells.

  5. Optimizing cell-free protein expression in CHO: Assessing small molecule mass transfer effects in various reactor configurations.

    Science.gov (United States)

    Peñalber-Johnstone, Chariz; Ge, Xudong; Tran, Kevin; Selock, Nicholas; Sardesai, Neha; Gurramkonda, Chandrasekhar; Pilli, Manohar; Tolosa, Michael; Tolosa, Leah; Kostov, Yordan; Frey, Douglas D; Rao, Govind

    2017-03-07

    Cell-free protein synthesis (CFPS) is an ideal platform for rapid and convenient protein production. However, bioreactor design remains a critical consideration in optimizing protein expression. Using turbo green fluorescent protein (tGFP) as a model, we tracked small molecule components in a Chinese Hamster Ovary (CHO) CFPS system to optimize protein production. Here, three bioreactors in continuous-exchange cell-free (CECF) format were characterized. A GFP optical sensor was built to monitor the product in real-time. Mass transfer of important substrate and by-product components such as nucleoside triphosphates (NTPs), creatine, and inorganic phosphate (Pi) across a 10-kDa MWCO cellulose membrane was calculated. Highest efficiency measured by tGFP yields were found in a microdialysis device configuration; while a negative effect on yield was observed due to limited mass transfer of NTPs in a dialysis cup configuration. In 24-well plate high-throughput CECF format, addition of up to 40 mM creatine phosphate in the system increased yields by up to ∼60% relative to controls. Direct ATP addition, as opposed to creatine phosphate addition, negatively affected the expression. Pi addition of up to 30 mM to the expression significantly reduced yields by over ∼40% relative to controls. Overall, data presented in this report serves as a valuable reference to optimize the CHO CFPS system for next-generation bioprocessing. This article is protected by copyright. All rights reserved.

  6. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO; Avaliacao do efeito radiomodificador da propolis em celulas de ovario de hamster chines (CHO-K1) e em celulas tumorais de prostata (PC3), irradiadas com CO-60

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Geyza Spigoti

    2011-07-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with {sup 60}Co {gamma} radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 {mu}g/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400{mu}/ml) in PC3 cells irradiated with 5 G{gamma}. The survival curves obtained were adequately fitted by a linear-quadratic model, where the {alpha} coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 {mu}g/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data

  7. Developement of serum-free media in CHO-DG44 cells using a central composite statistical design.

    Science.gov (United States)

    Parampalli, Ananth; Eskridge, Kent; Smith, Leonard; Meagher, Michael M; Mowry, Mark C; Subramanian, Anuradha

    2007-05-01

    A serum free medium was developed for the production of recombinant antibody against Botulinum A (BoNTA) using dihydrofolate reductase deficient Chinese Hamster Ovary Cells (CHO-DG44) in suspension culture. An initial control basal medium was prepared, which was similar in composition to HAM's F12: IMDM (1:1) supplemented with insulin, transeferrin, selenium and a lipid mixture. The vitamin concentration of the basal medium was twice that of HAM's F12: IMDM (1:1). CHO-DG44 cells expressing S25 antibody grew from 2 x 10(5) cells to maximum cell density of 1.04 x 10(6) cells/ml after 5 days in this control medium. A central composite design was used to identify optimal levels and interaction among five groups of medium components. These five groups were glutamine, Essential Amino Acids (EAA), Non Essential Amino Acids (NEAA), Insulin, Transferrin, Selenium (ITS), and lipids. Fifty experiments were carried out in four batches, with two controls in each batch. There was little effect of ITS and Lipid concentrations over the range studied, and glutamine concentration showed a strong interaction with EAA. The optimal concentrations of the variables studied were 2.5 mM Glutamine, 7.4 mM (2x) EAA, 1.4 mM (0.5x) NEAA, 1x ITS supplement, 0.7x Lipids supplement. The maximum viable cell density attained in the optimized medium was 1.4 x 10(6) cells/ml, a 35% improvement over the control culture, while the final antibody titer attained was 22 +/- 3.4 mug/mL, a 50% improvement.

  8. Using simple models to describe the kinetics of growth, glucose consumption, and monoclonal antibody formation in naive and infliximab producer CHO cells.

    Science.gov (United States)

    López-Meza, Julián; Araíz-Hernández, Diana; Carrillo-Cocom, Leydi Maribel; López-Pacheco, Felipe; Rocha-Pizaña, María Del Refugio; Alvarez, Mario Moisés

    2016-08-01

    Despite their practical and commercial relevance, there are few reports on the kinetics of growth and production of Chinese hamster ovary (CHO) cells-the most frequently used host for the industrial production of therapeutic proteins. We characterize the kinetics of cell growth, substrate consumption, and product formation in naive and monoclonal antibody (mAb) producing recombinant CHO cells. Culture experiments were performed in 125 mL shake flasks on commercial culture medium (CD Opti CHO™ Invitrogen, Carlsbad, CA, USA) diluted to different glucose concentrations (1.2-4.8 g/L). The time evolution of cell, glucose, lactic acid concentration and monoclonal antibody concentrations was monitored on a daily basis for mAb-producing cultures and their naive counterparts. The time series were differentiated to calculate the corresponding kinetic rates (rx = d[X]/dt; rs = d[S]/dt; rp = d[mAb]/dt). Results showed that these cell lines could be modeled by Monod-like kinetics if a threshold substrate concentration value of [S]t = 0.58 g/L (for recombinant cells) and [S]t = 0.96 g/L (for naïve cells), below which growth is not observed, was considered. A set of values for μmax, and Ks was determined for naive and recombinant cell cultures cultured at 33 and 37 °C. The yield coefficient (Yx/s) was observed to be a function of substrate concentration, with values in the range of 0.27-1.08 × 10(7) cell/mL and 0.72-2.79 × 10(6) cells/mL for naive and recombinant cultures, respectively. The kinetics of mAb production can be described by a Luedeking-Piret model (d[mAb]/dt = αd[X]/dt + β[X]) with values of α = 7.65 × 10(-7) µg/cell and β = 7.68 × 10(-8) µg/cell/h for cultures conducted in batch-agitated flasks and batch and instrumented bioreactors operated in batch and fed-batch mode.

  9. Establishment and evaluation of a murine ανβ3-integrin-expressing cell line with increased susceptibility to Foot-and-mouth disease virus.

    Science.gov (United States)

    Zhang, Wei; Lian, Kaiqi; Yang, Fan; Yang, Yang; Zhu, Zhijian; Zhu, Zixiang; Cao, Weijun; Mao, Ruoqing; Jin, Ye; He, Jijun; Guo, Jianhong; Liu, Xiangtao; Zheng, Haixue

    2015-01-01

    Integrin ανβ3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of ανβ3 integrin, a stable CHO-677 cell line expressing the murine ανβ3 heterodimer (designated as "CHO-677-mανβ3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits αν and β3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-mανβ3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-mανβ3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable ανβ3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of ανβ3 integrin, and as a cell model for FMDV research.

  10. Cloning and Expression of Luteinizing Hormone Subunits in Chinese Hamster Ovary Cell Line

    Directory of Open Access Journals (Sweden)

    Zeinab Soleimanifar

    2016-10-01

    Full Text Available Background: Luteinizing hormone (LH was secreted by the stimulating cells of the testes and ovaries in the anterior pituitary gland. The application of this hormone is in the treatment of men and women with infertility and amenorrhea respectively.Materials and Methods: In the present study the alpha and beta subunits of human LH gene were cloned into the pEGFP-N1 expression vector and produced the recombinant LH hormone in Chinese hamster ovary (CHO eukaryotic system.Results: Alpha and beta subunits of LH hormone were cloned between NheI and BamHI cut sites of pEGFP_N1 expression plasmid and confirmed by PCR.  Hormone expression was evaluated in CHO cell line by Western blotting using the specific antibody.Conclusion: Alpha and beta subunits of LH hormone were expressed in CHO cell line perfectly.

  11. Use of a Plackett-Burman statistical design to determine the effect of selected amino acids on monoclonal antibody production in CHO cells.

    Science.gov (United States)

    González-Leal, I J; Carrillo-Cocom, L M; Ramírez-Medrano, A; López-Pacheco, F; Bulnes-Abundis, D; Webb-Vargas, Y; Alvarez, M M

    2011-01-01

    Culture media design is central to the optimization of monoclonal antibody (mAb) production. Although general strategies do not currently exist for optimization of culture media, the combined use of statistical design and analysis of experiments and strategies based on simple material balances can facilitate culture media design. In this study, we evaluate the effect of selected amino acids on the growth rate and monoclonal antibody production of a Chinese hamster ovary DG-44 (CHO-DG44) cell line. These amino acids were selected based on their relative mass fraction in the specific mAb produced in this study, their consumption rate during bioreactor experiments, and also through a literature review. A Plackett-Burman statistical design was conducted to minimize the number of experiments needed to obtain statistically relevant information. The effect of this set of amino acids was evaluated during exponential cell culture (considering viable cell concentration and the specific growth rate as main output variables) and during the high cell-density stage (considering mAb final concentration and specific productivity as relevant output variables). For this particular cell line, leucine (Leu) and arginine (Arg) had the highest negative and positive effects on cell viability, respectively; Leu and threonine (Thr) had the highest negative effect on growth rate, and valine (Val) and Arg demonstrated the highest positive impact on mAb final concentration. Results suggest the pertinence of a two-stage strategy for amino acid supplementation, with a mixture optimized for cell growth and a different amino acid mixture for mAb production at high density.

  12. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    Directory of Open Access Journals (Sweden)

    Rudd Pauline M

    2011-10-01

    Full Text Available Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  13. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    LENUS (Irish Health Repository)

    Burleigh, Susan C

    2011-10-18

    Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO) were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG) was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  14. A mechanistic dissection of polyethylenimine mediated transfection of CHO cells: to enhance the efficiency of recombinant DNA utilization.

    Science.gov (United States)

    Mozley, Olivia L; Thompson, Ben C; Fernandez-Martell, Alejandro; James, David C

    2014-01-01

    In this study, we examine the molecular and cellular interactions that underpin efficient internalization and utilization of polyethylenimine (PEI):DNA complexes (polyplexes) by Chinese Hamster Ovary (CHO) cells. Cell surface polyplex binding and internalization was a biphasic process, consisting of an initial rapid Phase (I), lasting approximately 15 min, followed by a slower second Phase (II), saturating at approximately 240 min post transfection. The second Phase accounted for the majority (60-70%) of polyplex internalization. While cell surface heparan sulphate proteoglycans (HSPGs) were rapidly cointernalized with polyplexes during Phase I, cell surface polyplex binding was not dependent on HSPGs. However, Phase II polyplex internalization and HSPG regeneration onto the surface of trypsinized cells occurred at similar rates, suggesting that the rate of recycling of HSPG-containing membrane to the plasma membrane limits Phase II internalization rate. Under optimal transfection conditions, polyplexes had a near neutral surface charge (zeta potential) and cell surface binding was dependent on hydrophobic interactions, being significantly inhibited by both chemical sequestration of cholesterol from the plasma membrane and addition of nonionic surfactant. Induced alterations in polyplex zeta potential, using ferric (III) citrate to decrease surface charge and varying PEI:DNA ratio to increase surface charge, served to inhibit polyplex binding or reduce secreted alkaline phosphatase reporter expression and cell viability, respectively. To increase polyplex hydrophobicity and internalization an alkylated derivative of PEI, propyl-PEI, was chemically synthesized. Using Design of Experiments-Response Surface Modeling to optimize the transfection process, the function of propyl-PEI was compared to that of unmodified PEI in both parental CHO-S cells and a subclone (Clone 4), which exhibited superior transgene expression via an increased resistance to polyplex

  15. Lysophosphatidic acid activates peroxisome proliferator activated receptor-γ in CHO cells that over-express glycerol 3-phosphate acyltransferase-1.

    Directory of Open Access Journals (Sweden)

    Cliona M Stapleton

    Full Text Available Lysophosphatidic acid (LPA is an agonist for peroxisome proliferator activated receptor-γ (PPARγ. Although glycerol-3-phosphate acyltransferase-1 (GPAT1 esterifies glycerol-3-phosphate to form LPA, an intermediate in the de novo synthesis of glycerolipids, it has been assumed that LPA synthesized by this route does not have a signaling role. The availability of Chinese Hamster Ovary (CHO cells that stably overexpress GPAT1, allowed us to analyze PPARγ activation in the presence of LPA produced as an intracellular intermediate. LPA levels in CHO-GPAT1 cells were 6-fold higher than in wild-type CHO cells, and the mRNA abundance of CD36, a PPARγ target, was 2-fold higher. Transactivation assays showed that PPARγ activity was higher in the cells that overexpressed GPAT1. PPARγ activity was enhanced further in CHO-GPAT1 cells treated with the PPARγ ligand troglitazone. Extracellular LPA, phosphatidic acid (PA or a membrane-permeable diacylglycerol had no effect, showing that PPARγ had been activated by LPA generated intracellularly. Transient transfection of a vector expressing 1-acylglycerol-3-phosphate acyltransferase-2, which converts endogenous LPA to PA, markedly reduced PPARγ activity, as did over-expressing diacylglycerol kinase, which converts DAG to PA, indicating that PA could be a potent inhibitor of PPARγ. These data suggest that LPA synthesized via the glycerol-3-phosphate pathway can activate PPARγ and that intermediates of de novo glycerolipid synthesis regulate gene expression.

  16. Dynamic distribution of Ser-10 phosphorylated histone H3 in cytoplasm of MCF-7 and CHO cells during mitosis

    Institute of Scientific and Technical Information of China (English)

    Deng Wen LI; Qin YANG; Jia Tong CHEN; Hao ZHOU; Ru Ming LIU; Xi Tai HUANG

    2005-01-01

    The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determine its function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO were analyzed by indirect immunofluorescence staining with an antibody against phospho-H3. We found that the phosphorylation begins at early prophase, and spreads throughout the chromosomes at late prophase. At metaphase, most of the phosphoH3 aggregates at the end of the condensed entity of chromosomes at equatorial plate. During anaphase and telophase,the fluorescent signal of phospho-H3 is detached from chromosomes into cytoplasm. At early anaphase, phospho-H3shows ladder bands between two sets of separated chromosome, and forms "sandwich-like structure" when the chromosomes condensed. With the cleavage progressing, the "ladders" of the histone contract into a bigger bright dot. Then the histone aggregates and some of compacted microtubules in the midbody region are composed into a "bar-like"complex to separate daughter cells. The daughter cells seal their plasma membrane along with the ends of the "bar",inside which locates microtubules and modified histones, to finish the cytokinesis and keep the "bar complex" out of the cells. The specific distribution and kinetics of phospho-H3 in cytoplasm suggest that the modified histones may take part in the formation of midbody and play a crucial role in cytokinesis.

  17. Transfection of the cloned human excision repair gene ERCC-1 to UV-sensitive CHO mutants only corrects the repair defect in complementation group 2 mutants.

    NARCIS (Netherlands)

    M. van Duin (Mark); J.H. Janssen; J. de Wit (Jan); J.H.J. Hoeijmakers (Jan); L.H. Thompson; D. Bootsma (Dirk); A. Westerveld (Andries)

    1988-01-01

    textabstractThe human DNA-excision repair gene ERCC-1 is cloned by its ability to correct the excision-repair defect of the ultraviolet light- and mitomycin-C-sensitive CHO mutant cell line 43-3B. This mutant is assigned to complementation group 2 of the excision-repair-deficient CHO mutants. In ord

  18. Comparison of the behavior of CHO cells during cultivation in 24-square deep well microplates and conventional shake flask systems

    Directory of Open Access Journals (Sweden)

    Kirti Chaturvedi

    2014-06-01

    Full Text Available In biopharmaceutical production, the optimization of cell culture media and supplementation is a vital element of process development. Optimization is usually achieved through the screening of multiple media, feed and feeding strategies. However, most screening is performed in shake flasks, which makes the screening process very time consuming and inefficient. The use of small scale culture systems for the screening process can aid in the ability to screen multiple formulations during process development. In order to assess the suitability of 24 deep well (24DW plates with the Duetz sandwich-covers as a small scale culture system for process development, we have tested growth and production performance of CHO cells in 24DW plates and conventional shake flask cultures. Multiple studies were performed to assess well-to-well and plate-to-plate variability in 24DW plates. Additional studies were performed to determine the applicability of 24DW plates for cell culture medium and supplement screening in batch and fed batch processes. Cultures in 24DW plates exhibited similar kinetics in growth, viability and protein production to those cultured in shake flasks, suggesting that 24DW plates with Duetz sandwich-covers can be effectively used for high throughput cell culture screening.

  19. A Murine Fibroblast Growth Factor (FGF) Receptor Expressed in CHO Cells is Activated by Basic FGF and Kaposi FGF

    Science.gov (United States)

    Mansukhani, Alka; Moscatelli, David; Talarico, Daniela; Levytska, Vera; Basilico, Claudio

    1990-06-01

    We have cloned a murine cDNA encoding a tyrosine kinase receptor with about 90% similarity to the chicken fibroblast growth factor (FGF) receptor and the human fms-like gene (FLG) tyrosine kinase. This mouse receptor lacks 88 amino acids in the extracellular portion, leaving only two immunoglobulin-like domains compared to three in the chicken FGF receptor. The cDNA was cloned into an expression vector and transfected into receptor-negative CHO cells. We show that cells expressing the receptor can bind both basic FGF and Kaposi FGF. Although the receptor binds basic FGF with a 15- to 20-fold higher affinity, Kaposi FGF is able to induce down-regulation of the receptor to the same extent as basic FGF. The receptor is phosphorylated upon stimulation with both FGFs, DNA synthesis is stimulated, and a proliferative response is produced in cells expressing the receptor, whereas cells expressing the cDNA in the antisense orientation show none of these responses to basic FGF or Kaposi FGF. Thus this receptor can functionally interact with two growth factors of the FGF family.

  20. Genomic landscapes of Chinese hamster ovary cell lines as revealed by the Cricetulus griseus draft genome

    DEFF Research Database (Denmark)

    Lewis, Nathan E; Liu, Xin; Li, Yuxiang

    2013-01-01

    . This analysis identified hamster genes missing in different CHO cell lines, and detected >3.7 million single-nucleotide polymorphisms (SNPs), 551,240 indels and 7,063 copy number variations. Many mutations are located in genes with functions relevant to bioprocessing, such as apoptosis. The details...

  1. GD3 expression in CHO-K1 cells increases growth rate, induces morphological changes, and affects cell-substrate interactions.

    Science.gov (United States)

    Daniotti, Jose L; Zurita, Adolfo R; Trindade, Vera M T; Maccioni, Hugo J F

    2002-11-01

    We have generated a panel of CHO-K1 cell clones with different glycolipid compositions by stable transfection of appropriate glycosyltransferases and studied the morphological and growth phenotype of a clone stably expressing Sial-T2. Compared with the GM3 expressing parental cells, Sial-T2 transfectants show low expression of GM3 and neo expression of GD3 and GT3. These cells show about 60% reduction of the mean cell area, and about 2-fold increase of the mean colony area and growth rate. Cells over expressing Sial-T2 showed a flattened appearance, and with time in culture they detached from the substrate leaving adhered material that was GD3 immunoreactive. No apoptotic or proteome differences could be detected in the Sial-T2 transfectants. Thus, increased expression of GD3 and GT3 influence parameters of growth and social behavior of CHO-K1 cells. However, the molecular and cellular basis underlying these influences requires further investigation.

  2. Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

    DEFF Research Database (Denmark)

    Jacobsen, Stine Engesgaard; Nørskov-Lauritsen, Lenea; Thomsen, Alex Rojas Bie;

    2013-01-01

    receptor has been suggested to couple to multiple G protein classes albeit via indirect methods. Thus, the exact ligand preferences and signaling pathways are yet to be elucidated. In the present study, we generated a Chinese hamster ovary (CHO) cell line that stably expresses mouse GPRC6A. In an effort...... of the stable CHO cell line with robust receptor responsiveness and optimization of the highly sensitive homogeneous time resolved fluorescence technology allow fast assessment of Gq activation without previous manipulations like cotransfection of mutated G proteins. This cell-based assay system for GPRC6A...

  3. Modification of pGH cDNA using the first intron and adenovirus-mediated expression in CHO cells

    Institute of Scientific and Technical Information of China (English)

    李秀锦; 仲飞; 齐顺章

    2003-01-01

    Objective This study was conducted to investigate the function of the first intron of porcine growth hormone (pGH) gene in the gene expression.Methods PCR method was used to amplify the first intron from pig genomic DNA. The intron was then inserted into pGH cDNA to construct pGH cDNA-intron (pGH cDNA-in). The recombinant adenoviruses containing pGH cDNA and pGH cDNA-in genes under control of CMV promoter were generated by homologous recombination method in HEK 293 cells respectively. The effect of the first intron on gene expression was evaluated by comparing the expression levels of pGH cDNA-in and pGH cDNA mediated by adenovirus vectors in CHO cells.Results The expression level of pGH cDNA containing the first intron increased by 117%, which was significantly higher than that of pGH cDNA without the intron (P<0.001). Conclusion The first intron of pGH gene has the function to improve pGH gene expression.

  4. Sulfhydryl compounds inhibit the cyto- and geno-toxicity of o-phenylphenol metabolites in CHO-K1 cells.

    Science.gov (United States)

    Tayama, S; Nakagawa, Y

    1991-01-01

    The effects of cysteine and reduced glutathione (GSH) on the genotoxicity of o-phenylphenol (OPP) and its metabolites, phenylhydroquinone (PHQ) and phenylbenzoquinone (PBQ), were examined using the frequency of sister-chromatid exchanges (SCEs) and chromosome aberrations in CHO-K1 cells as parameters. Cytotoxic (cell-progression delay) and cytogenetic effects induced by a 3-h treatment with OPP, PHQ (100 micrograms/ml) or PBQ (50 micrograms/ml) with S9 mix after a 27-h expression time were inhibited by cysteine or GSH (3-10 mM). Materials corresponding to the cysteine or GSH adducts were found by HPLC in each incubation mixture. In the culture without S9 mix, PHQ and PBQ showed severe cytotoxicity since no metaphases could be obtained at doses over 25 and 5 micrograms/ml, respectively, and the sulfhydryl compounds inhibited the toxicity by the formation of adducts with PBQ and by inhibiting the formation of PBQ in the case of PHQ. With PHQ, the sulfhydryl compounds appeared to inhibit autooxidation. However, the sulfhydryl compounds did not inhibit the cytotoxic and cytogenetic effects caused by OPP in the cell mixture without S9 mix, but on the contrary intensified them. No adduct formation was detected in the incubation solution. On the basis of these results, it is considered that electrophilic quinone (PBQ) and/or semiquinone (phenylsemiquinone, PSQ) radicals, capable of binding to nucleophilic small molecules (such as cysteine and GSH) or (biological) macromolecules, are produced from metabolite PHQ in metabolic oxidation of OPP, and induce cyto- and geno-toxic effects in the cells. The cyto- and geno-toxic effects of OPP itself to the cells are clearly independent of any electrophilic radical reaction.

  5. Regulated expression of the rat recombinant P2X(3) receptor in stably transfected CHO-K1 tTA cells.

    Science.gov (United States)

    Lachnit, W G; Oglesby, I B; Gever, J R; Gever, M; Huang, C; Li, X C; Jin, H; McGivern, J G; Ford, A P

    2000-07-01

    In this report, the regulatable expression by tetracycline of the rat recombinant P2X(3) receptor in stably transfected Chinese hamster ovary (CHO-K1) expressing the tetracycline-controlled transactivator (tTA) is described. cDNA encoding the rat P2X(3)-receptor was subcloned into pTRE (a tetracycline-repressible expression vector) which was used to transfect stably CHO-K1 tTA cells. Using whole cell patch clamp techniques, 100 microM ATP evoked inward currents of 2.9+/-1.6 nA in transfected cells grown in the absence of tetracycline (tet-). The P2X(3) receptor protein was detectable by immunoblot as early as 24 h and protein expression levels continued to increase as much as 192 h following activation of tTA by the removal of the antibiotic. Saturation binding isotherms using [35S]ATP gamma S yielded a pK(d) of 8.2+/-0.1 and a B(max) of 31.9+/-3.5 pmol/mg protein in tet- cell membranes and a pK(d) of 8.1+/-0.1 and a B(max) of 5.8+/-0.8 pmol/mg protein in tet+ cell membranes. The agonist ligands 2MeSATP and alpha beta MeATP displaced the binding of [35S]ATP gamma S in tet- cell membranes with very high affinity, yielding pIC(50) values of 9.4+/-0.2 and 7.5+/-0. 2, respectively. In tet+ cell membrane, displacement of [35S]ATP gamma S by 2MeSATP and alpha beta MeATP was of much lower affinity (pIC(50) values of 7.8 and 6.2, respectively). ATP, ADP and UTP showed similar displacement of [35S]ATP gamma S binding in tet- and tet+ cell membranes. In other experiments, cytosolic Ca(2+) was monitored using the fluorescent indicator, fluo-3. Increases in cytosolic Ca(2+) were elicited by 100 nM alpha beta MeATP in tet- cells while no increases in cytosolic Ca(2+) were detected below 100 microM alpha beta MeATP in either tet+ cells or untransfected cells. These calcium responses to alpha beta MeATP had a pEC(50) of 6.7 and were transient, returning to baseline within 120 s. Suramin produced concentration-dependent, parallel, dextral shifts of E/[A] curves to alpha beta Me

  6. CLO : The cell line ontology

    NARCIS (Netherlands)

    Sarntivijai, Sirarat; Lin, Yu; Xiang, Zuoshuang; Meehan, Terrence F.; Diehl, Alexander D.; Vempati, Uma D.; Schuerer, Stephan C.; Pang, Chao; Malone, James; Parkinson, Helen; Liu, Yue; Takatsuki, Terue; Saijo, Kaoru; Masuya, Hiroshi; Nakamura, Yukio; Brush, Matthew H.; Haendel, Melissa A.; Zheng, Jie; Stoeckert, Christian J.; Peters, Bjoern; Mungall, Christopher J.; Carey, Thomas E.; States, David J.; Athey, Brian D.; He, Yongqun

    2014-01-01

    Background: Cell lines have been widely used in biomedical research. The community-based Cell Line Ontology (CLO) is a member of the OBO Foundry library that covers the domain of cell lines. Since its publication two years ago, significant updates have been made, including new groups joining the CLO

  7. Reduced cytotoxicity in PCB-exposed Chinese Hamster Ovary (CHO) cells pretreated with vitamin E.

    Science.gov (United States)

    Murati, Teuta; Šimić, Branimir; Pleadin, Jelka; Vukmirović, Maja; Miletić, Marina; Durgo, Ksenija; Kniewald, Jasna; Kmetič, Ivana

    2017-01-01

    The aim of this study was to evaluate protective effects of vitamin E (50 -150 μM) in ovary cells upon cytotoxic effects induced by two structurally distinct PCB congeners - planar "dioxin-like" PCB 77 and non-planar di-ortho-substituted PCB 153 with an emphasis on identifying differences in the mechanism of vitamin E action depending on the structure of congeners. Application of three bioassays confirmed that PCBs decrease ovarian cell proliferation with slightly profound effects of PCB 77. PCB - induced ROS production and lipid peroxidation were significant for both congeners with also more noticeable effect for PCB 77. Vitamin E pre-incubation has improved viability of cells, reduced ROS formation and lipid peroxidation induced by PCBs' treatment. Preincubation with vitamin E was more effective when cells where treated with non-planar PCB 153. Altogether, vitamin E action was protective, congener specific and more effective when ovary cells were exposed to ortho-substituted PCB congener.

  8. Comparative study of the cytotoxic and genotoxic effects of titanium oxide and aluminium oxide nanoparticles in Chinese hamster ovary (CHO-K1) cells.

    Science.gov (United States)

    Di Virgilio, A L; Reigosa, M; Arnal, P M; Fernández Lorenzo de Mele, M

    2010-05-15

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO(2)) and aluminium oxide (Al(2)O(3)) nanoparticles (NPs) on Chinese hamster ovary (CHO-K1) cells using neutral red (NR), mitochondrial activity (by MTT assay), sister chromatid exchange (SCE), micronucleus (MN) formation, and cell cycle kinetics techniques. Results showed a dose-related cytotoxic effect evidenced after 24h by changes in lysosomal and mitochondrial dehydrogenase activity. Interestingly, transmission electronic microscopy (TEM) showed the formation of perinuclear vesicles in CHO-K1 cells after treatment with both NPs during 24h but no NP was detected in the nuclei. Genotoxic effects were shown by MN frequencies which significantly increased at 0.5 and 1 microg/mL TiO(2) and 0.5-10 microg/mL Al(2)O(3). SCE frequencies were higher for cells treated with 1-5 microg/mL TiO(2). The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO(2). No SCE induction was achieved after treatment with 1-25 microg/mL Al(2)O(3). In conclusion, findings showed cytotoxic and genotoxic effects of TiO(2) and Al(2)O(3) NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  9. Cross-scale predictive modeling of CHO cell culture growth and metabolites using Raman spectroscopy and multivariate analysis.

    Science.gov (United States)

    Berry, Brandon; Moretto, Justin; Matthews, Thomas; Smelko, John; Wiltberger, Kelly

    2015-01-01

    Multi-component, multi-scale Raman spectroscopy modeling results from a monoclonal antibody producing CHO cell culture process including data from two development scales (3 L, 200 L) and a clinical manufacturing scale environment (2,000 L) are presented. Multivariate analysis principles are a critical component to partial least squares (PLS) modeling but can quickly turn into an overly iterative process, thus a simplified protocol is proposed for addressing necessary steps including spectral preprocessing, spectral region selection, and outlier removal to create models exclusively from cell culture process data without the inclusion of spectral data from chemically defined nutrient solutions or targeted component spiking studies. An array of single-scale and combination-scale modeling iterations were generated to evaluate technology capabilities and model scalability. Analysis of prediction errors across models suggests that glucose, lactate, and osmolality are well modeled. Model strength was confirmed via predictive validation and by examining performance similarity across single-scale and combination-scale models. Additionally, accurate predictive models were attained in most cases for viable cell density and total cell density; however, these components exhibited some scale-dependencies that hindered model quality in cross-scale predictions where only development data was used in calibration. Glutamate and ammonium models were also able to achieve accurate predictions in most cases. However, there are differences in the absolute concentration ranges of these components across the datasets of individual bioreactor scales. Thus, glutamate and ammonium PLS models were forced to extrapolate in cases where models were derived from small scale data only but used in cross-scale applications predicting against manufacturing scale batches.

  10. Expression and bioactivity of recombinant human serum albumin and dTMP fusion proteins in CHO cells.

    Science.gov (United States)

    Ru, Yi; Zhi, Dejuan; Guo, Dingding; Wang, Yong; Li, Yang; Wang, Meizhu; Wei, Suzhen; Wang, Haiqing; Wang, Na; Che, Jingmin; Li, Hongyu

    2016-09-01

    The 14-amino acid (IEGPTLRQWLAARA) thrombopoietin mimetic peptide (TMP) shares no sequence homology with native thrombopoietin (TPO). When dimerized, it displays a high-binding affinity for the TPO receptor and has equipotent bioactivity with recombinant human TPO (rhTPO) in stimulating proliferation and maturation of megakaryocytes in vitro. However, TMP is limited for clinical usage because of its short half-life in vivo. In this study, fusion proteins that composed of tandem dimer of TMP (dTMP) genetically fused at the C- or N-terminus of human serum albumin (HSA) were separately expressed in Chinese hamster ovary (CHO) cells. In vitro bioactivity assays showed that purified fusion proteins promoted the proliferation of megakaryocytes in a dose-dependent manner and activated signal transducer and activator of transcription (STAT) pathway in TPO receptor-dependent manner. Following subcutaneous administration, both HSA-dTMP and dTMP-HSA significantly elevated peripheral platelet counts in normal mice in a dose-dependent manner. In addition, fusion with HSA successfully prolonged dTMP half-life in mice. However, when HSA was fused at the C-terminus of dTMP, the bioactivity of dTMP-HSA was about half of that of HSA-dTMP. In conclusion, these results suggested that HSA/dTMP fusion proteins might be potential drugs for thrombocytopenia and, when HSA was fused at the N-terminus of dTMP, the fusion protein had a higher activity.

  11. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    DEFF Research Database (Denmark)

    Hefzi, Hooman; Ang, Kok Siong; Hanscho, Michael

    2016-01-01

    in CHO and associated them with >1,700 genes in the Cricetulus griseus genome. The genome-scale metabolic model based on this reconstruction, iCHO1766, and cell-line-specific models for CHO-K1, CHO-S, and CHO-DG44 cells provide the biochemical basis of growth and recombinant protein production......Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways...... simulations show that the metabolic resources in CHO are more than three times more efficiently utilized for growth or recombinant protein synthesis following targeted efforts to engineer the CHO secretory pathway. This model will further accelerate CHO cell engineering and help optimize bioprocesses....

  12. Oxygen supply for CHO cells immobilized on a packed-bed of Fibra-Cel disks.

    Science.gov (United States)

    Meuwly, F; Loviat, F; Ruffieux, P-A; Bernard, A R; Kadouri, A; von Stockar, U

    2006-03-05

    Packed-bed bioreactors (PBR) have proven to be efficient systems to culture mammalian cells at very high cell density in perfusion mode, thus leading to very high volumetric productivity. However, the immobilized cells must be continuously supplied with all nutrients in sufficient quantities to remain viable and productive over the full duration of the perfusion culture. Among all nutrients, oxygen is the most critical since it is present at very low concentration due to its low solubility in cell culture medium. This work presents the development of a model for oxygenation in a packed-bed bioreactor system. The experimental system used to develop the model was a packed-bed of Fibra-Cel disk carriers used to cultivate Chinese Hamster Ovary cells at high density ( approximately 6.1 x 10(7) cell/mL) in perfusion mode. With the help of this model, it was possible to identify if a PBR system is operated in optimal or sub-optimal conditions. Using the model, two options were proposed, which could improve the performance of the basal system by about twofold, that is, by increasing the density of immobilized cells per carrier volume from 6.1 x 10(7) to 1.2 x 10(8) cell/mL, or by increasing the packed-bed height from 0.2 to 0.4 m. Both strategies would be rather simple to test and implement in the packed-bed bioreactor system used for this study. As a result, it would be possible to achieve a substantial improvement of about twofold higher productivity as compared with the basal conditions.

  13. Clastogenic effects of biosynthetic human growth hormone in Snell dwarf mice and CHO cells in vitro

    NARCIS (Netherlands)

    Buul, P.P.W. van; Buul-Offers, S. van

    1984-01-01

    Treatment of Snell dwarf mice with high concentrations of human growth hormone from pituitaries as well as of bacterial origin, significantly increased the frequencies of chromosomal aberrations in bone-marrow cells, as measured by the micronucleus test. In vitro treatment of Chinese hamster ovary (

  14. Test for Chemical Induction of Chromosome Aberrations in Cultured Chinese Hamster (CHO) Cells With and Without Metabolic Activation. Test Article. Diethylene triamine trinitrate (DETN)

    Science.gov (United States)

    2010-02-25

    chromatid interchanges between chromosomes leading to four-armed configurations. This could be asymmetrical with formation of a dicentric and an acentric...fragment which may be misaligned and a shortened monocentric chromosome , and where there is no sister chromatid union. Dicentric - an asymmetrical...Test for Chemical Induction of Chromosome Aberrations in Cultured Chinese Hamster Ovary (CHO) Cells With and Without Metabolic Activation Test

  15. Effect of mild-thiol reducing agents and alpha2,3-sialyltransferase expression on secretion and sialylation of recombinant EPO in CHO cells.

    Science.gov (United States)

    Chang, Kern Hee; Jeong, Yeon Tae; Kwak, Chan Yeong; Choi, One; Kim, Jung Hoe

    2013-05-01

    We have previously reported that N-acetylcysteine (NAC) not only delayed apoptosis but also enhanced the production of recombinant erythropoietin (EPO) in Chinese hamster ovary (CHO) cell culture. To investigate the production enhancement mechanism, the effects of similar thiolreducing agents were studied. Intriguingly, all mild reducing agents examined including mercaptoethanesulfonic acid (MESNA), thiolactic acid (TLA), and thioglycolate (TG) were shown to block apoptosis and increase EPO production. A pulse-chase study of EPO secretion revealed that all four thiol-reducing agents increased the EPO secretion rate; among them TLA showed the highest rate. In terms of product quality, the sialic acid content of the glycoprotein is one of the most important factors. It was reported that a number of glycoproteins produced by CHO cells often have incomplete sialylation, particularly under high-producing conditions. Human alpha2,3-sialyltransferase (alpha2,3-ST) was introduced into EPO-producing CHO cells in order to compensate for the reduced sialylation during supplementation with NAC. When alpha2,3-ST was expressed in the presence of NAC, reduced sialylation was restored and an even more sialylated EPO was produced. Thus, our study is significant in that it offers increased EPO production while still allowing the prevention of decreased sialylation of EPO.

  16. In Vitro Chromosome Aberrations Study in Chinese Hamster Ovary (CHO) Cells

    Science.gov (United States)

    2016-06-07

    activity offE-13. The mouse bone micronucleus assay is an in vivo test system which can determine the ability of a compound to induce micronuclei...CELLS Project No. ILS A073-004 Sponsor’s Study Number DAADOS-91-C-00 18 Test Substance FE-13 ILS Repository No. 96-01 Final Report Date May...24, 1996 Sponsor U.S. CHPPM Bldg. E-21 00 Aberdeen Proving Ground, MD 21005 Testing Facility Integrated Laboratory Systems 800-12 Capitola

  17. Human cystatin C forms an inactive dimer during intracellular trafficking in transfected CHO cells

    DEFF Research Database (Denmark)

    Merz, G S; Benedikz, Eirikur; Schwenk, V

    1997-01-01

    To define the cellular processing of human cystatin C as well as to lay the groundwork for investigating its contribution to lcelandic Hereditary Cerebral Hemorrhage with Amyloidosis (HCHWA-I), we have characterized the trafficking, secretion, and extracellular fate of human cystatin C...... that the cystatin C dimer, formed during intracellular trafficking, is converted to monomer at or before secretion. Cells in which exit from the endoplasmic reticulum (ER) was blocked with brefeldin A contained the 33 kDa species, indicating that cystatin C dimerization occurs in the ER. After removal of brefeldin......, presumably as a consequence of the low pH of late endosome/lysosomes. As a dimer, cystatin C would be prevented from inhibiting the lysosomal cysteine proteases. These results reveal a novel mechanism, transient dimerization, by which cystatin C is inactivated during the early part of its trafficking through...

  18. Feeding lactate for CHO cell culture processes: impact on culture metabolism and performance.

    Science.gov (United States)

    Li, Jincai; Wong, Chun Loong; Vijayasankaran, Natarajan; Hudson, Terry; Amanullah, Ashraf

    2012-05-01

    Lactate has long been regarded as one of the key metabolites of mammalian cell cultures. High levels of lactate have clear negative impacts on cell culture processes, and therefore, a great amount of efforts have been made to reduce lactate accumulation and/or to induce lactate consumption in the later stage of cultures. However, there is virtually no report on the impact of lactate depletion after initial accumulation. In this work, we observed that glucose uptake rate dropped over 50% at the onset of lactate consumption, and that catabolism of alanine due to lactate depletion led to ammonium accumulation. We explored the impact of feeding lactate as well as pyruvate to the cultures. In particular, a strategy was employed where CO(2) was replaced by lactic acid for culture pH control, which enabled automatic lactate feeding. The results demonstrated that lactate or pyruvate can serve as an alternative or even preferred carbon source during certain stage of the culture in the presence of glucose, and that by feeding lactate or pyruvate, very low levels of ammonia can be achieved throughout the culture. In addition, low levels of pCO(2) were also maintained in these cultures. This was in strong contrast to the control cultures where lactate was depleted during the culture, and ammonia and pCO(2) build-up were significant. Culture growth and productivity were similar between the control and lactate-fed cultures, as well as various product quality attributes. To our knowledge, this work represents the first comprehensive study on lactate depletion and offers a simple yet effective strategy to overcome ammonia and pCO(2) accumulation that could arise in certain cultures due to early depletion of lactate.

  19. Production of Highly Sialylated Recombinant Glycoproteins Using Ricinus communis Agglutinin-I-Resistant CHO Glycosylation Mutants.

    Science.gov (United States)

    Goh, John S Y; Chan, Kah Fai; Song, Zhiwei

    2015-01-01

    The degree of sialylation of therapeutic glycoproteins affects its circulatory half-life and efficacy because incompletely sialylated glycoproteins are cleared from circulation by asialoglycoprotein receptors present in the liver cells. Mammalian expression systems, often employed in the production of these glycoprotein drugs, produce heterogeneously sialylated products. Here, we describe how to produce highly sialylated glycoproteins using a Chinese hamster ovary (CHO) cell glycosylation mutant called CHO-gmt4 with human erythropoietin (EPO) as a model glycoprotein. The protocol describes how to isolate and characterize the CHO glycosylation mutants and how to assess the sialylation of the recombinant protein using isoelectric focusing (IEF). It further describes how to inactivate the dihydrofolate reductase (DHFR) gene in these cells using zinc finger nuclease (ZFN) technology to enable gene amplification and the generation of stable cell lines producing highly sialylated EPO.

  20. Establishment of a mammalian cell line suitable for industrial production of recombinant protein using mutations induced by high-energy beam radiation.

    Science.gov (United States)

    Chida, Yasuhito; Takagi, Keiichi; Terada, Satoshi

    2013-12-01

    Mammalian cells are extensively used for production of biopharmaceuticals. Most cells used in industry have infinite proliferative capacity, which provides a high number of cells and corresponding productivity. However, infinite cells will continue to multiply even after cell density reaches sufficient levels. This excess proliferation aggravates the culture environment and induces low productivity. Therefore, after cell density reaches sufficient levels, downregulation of proliferation would prevent such aggravation and extend the culture period and improve productivity. To realize such suitable proliferation, we aimed to establish a novel cell line whose proliferation was spontaneously downregulated after reaching a sufficient population level. Mutagenesis using high-energy beam irradiation was used. CHO-DP12 cells were irradiated with 2.5 Gy X-rays and screened with hydroxyurea and 5-fluorouracil to eliminate any cells multiplying after confluence and to concentrate desired mutants. One clone was established and named CHO-M1. Cell cycle analysis indicated that CHO-M1 cells had a similar cell cycle profile in the exponential growth phase, but cells rapidly accumulated in G1 phase just before confluence and did not progress through the cell cycle. This suggested that until confluence, proliferation of CHO-M1 was similar to parental CHO, but after confluence, it was inhibited and under G1 arrest. The specific antibody production rate of CHO-M1 was kept high, even after confluence, while that of parental CHO was drastically decreased in stationary phase. These results suggest that the desired cell line was successfully established and that high-energy beam irradiation could be an efficient mutagenic technique for breeding industrial cells.

  1. Macrophage receptor with collagenous structure (MARCO) is a dynamic adhesive molecule that enhances uptake of carbon nanotubes by CHO-K1 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Seishiro, E-mail: seishiro@nies.go.jp [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Fujitani, Yuji; Furuyama, Akiko [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Kanno, Sanae [Department of Legal Medicine, St. Marianna School of Medicine (Japan)

    2012-02-15

    The toxicity of carbon nanotubes (CNTs), a highly promising nanomaterial, is similar to that of asbestos because both types of particles have a fibrous shape and are biopersistent. Here, we investigated the characteristics of macrophage receptor with collagenous structure (MARCO), a membrane receptor expressed on macrophages that recognizes environmental or unopsonized particles, and we assessed whether and how MARCO was involved in cellular uptake of multi-walled CNTs (MWCNTs). MARCO-transfected Chinese hamster ovary (CHO-K1) cells took up polystyrene beads irrespective of the particle size (20 nm–1 μm). In the culture of MARCO-transfected CHO-K1 cells dendritic structures were observed on the bottom of culture dishes, and the edges of these dendritic structures were continually renewed as the cell body migrated along the dendritic structures. MWCNTs were first tethered to the dendritic structures and then taken up by the cell body. MWCNTs appeared to be taken up via membrane ruffling like macropinocytosis, rather than phagocytosis. The cytotoxic EC{sub 50} value of MWCNTs in MARCO-transfected CHO-K1 cells was calculated to be 6.1 μg/mL and transmission electron microscopic observation indicated that the toxicity of MWCNTs may be due to the incomplete inclusion of MWCNTs by the membrane structure. -- Highlights: ►Carbon nanotubes (CNTs) were tethered to MARCO in vitro. ►CNTs were taken up rapidly into the cell body via MARCO by membrane ruffling. ►The incomplete inclusion of CNTs by membranes caused cytotoxicity.

  2. Endoplasmic reticulum-directed recombinant mRNA displays subcellular localization equal to endogenous mRNA during transient expression in CHO cells

    DEFF Research Database (Denmark)

    Beuchert Kallehauge, Thomas; Kol, Stefan; Andersen, Mikael Rørdam;

    2016-01-01

    When expressing pharmaceutical recombinant proteins in mammalian cells, the protein is commonly directed through the secretory pathway, in a signal peptide-dependent manner, to acquire specific post-translational modifications and to facilitate secretion into the culture medium. One key premise...... for this is the direction of the mRNA encoding the recombinant protein to the surface of the endoplasmic reticulum (ER) for subsequent protein translocation into the secretory pathway. To evaluate the efficiency of this process in Chinese hamster ovary (CHO) cells, the subcellular localization of recombinant mRNA encoding...

  3. Fast intracellular dissolution and persistent cellular uptake of silver nanoparticles in CHO-K1 cells: implication for cytotoxicity

    DEFF Research Database (Denmark)

    Jiang, Xiumei; Miclaus, Teodora; Wang, Liming

    2015-01-01

    species, and cytotoxicity of Ag NPs (15.9 ± 7.6 nm) in Chinese hamster ovary cell subclone K1 cells, a cell line recommended by the OECD for genotoxicity studies. Quantification of intracellular nanoparticle uptake and ion release was performed through inductively coupled plasma mass spectrometry. X....... Subsequent cytotoxicity studies show that Ag NPs decrease cell viability and increase ROS production. Pre-incubation with N-acetyl-l-cysteine, an efficient antioxidant and Ag+ chelator, diminished the cytotoxicity caused by Ag NPs or Ag+ exposure. Our study suggests that the cytotoxicity mechanism of Ag NPs...

  4. Comparative study of the cytotoxic and genotoxic effects of titanium oxide and aluminium oxide nanoparticles in Chinese hamster ovary (CHO-K1) cells

    Energy Technology Data Exchange (ETDEWEB)

    Di Virgilio, A.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata (1900) (Argentina); Reigosa, M. [Instituto Multidisciplinario de Biologia Celular (IMBICE), Calle 526 y Camino Gral. Belgrano (entre 10 y 11), La Plata 1900 (Argentina); Arnal, P.M. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina); Fernandez Lorenzo de Mele, M., E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina)

    2010-05-15

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO{sub 2}) and aluminium oxide (Al{sub 2}O{sub 3}) nanoparticles (NPs) on Chinese hamster ovary (CHO-K1) cells using neutral red (NR), mitochondrial activity (by MTT assay), sister chromatid exchange (SCE), micronucleus (MN) formation, and cell cycle kinetics techniques. Results showed a dose-related cytotoxic effect evidenced after 24 h by changes in lysosomal and mitochondrial dehydrogenase activity. Interestingly, transmission electronic microscopy (TEM) showed the formation of perinuclear vesicles in CHO-K1 cells after treatment with both NPs during 24 h but no NP was detected in the nuclei. Genotoxic effects were shown by MN frequencies which significantly increased at 0.5 and 1 {mu}g/mL TiO{sub 2} and 0.5-10 {mu}g/mL Al{sub 2}O{sub 3}. SCE frequencies were higher for cells treated with 1-5 {mu}g/mL TiO{sub 2}. The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO{sub 2}. No SCE induction was achieved after treatment with 1-25 {mu}g/mL Al{sub 2}O{sub 3}. In conclusion, findings showed cytotoxic and genotoxic effects of TiO{sub 2} and Al{sub 2}O{sub 3} NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  5. Evidence for transketolase-like TKTL1 flux in CHO cells based on parallel labeling experiments and (13)C-metabolic flux analysis.

    Science.gov (United States)

    Ahn, Woo Suk; Crown, Scott B; Antoniewicz, Maciek R

    2016-09-01

    The pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. It provides precursors for the biosynthesis of nucleotides and contributes to the production of reducing power in the form of NADPH. It has been hypothesized that mammalian cells may contain a hidden reaction in PPP catalyzed by transketolase-like protein 1 (TKTL1) that is closely related to the classical transketolase enzyme; however, until now there has been no direct experimental evidence for this reaction. In this work, we have applied state-of-the-art techniques in (13)C metabolic flux analysis ((13)C-MFA) based on parallel labeling experiments and integrated flux fitting to estimate the TKTL1 flux in CHO cells. We identified a set of three parallel labeling experiments with [1-(13)C]glucose+[4,5,6-(13)C]glucose, [2-(13)C]glucose+[4,5,6-(13)C]glucose, and [3-(13)C]glucose+[4,5,6-(13)C]glucose and developed a new method to measure (13)C-labeling of fructose 6-phosphate by GC-MS that allows intuitive interpretation of mass isotopomer distributions to determine key fluxes in the model, including glycolysis, oxidative PPP, non-oxidative PPP, and the TKTL1 flux. Using these tracers we detected a significant TKTL1 flux in CHO cells at the stationary phase. The flux results suggest that the main function of oxidative PPP in CHO cells at the stationary phase is to fuel the TKTL1 reaction. Overall, this study demonstrates for the first time that carbon atoms can be lost in the PPP, by means other than the oxidative PPP, and that this loss of carbon atoms is consistent with the hypothesized TKTL1 reaction in mammalian cells.

  6. 炭疽受体CMG2-Fc融合蛋白在CHO细胞中的表达、纯化与鉴定%Expression,Purification and Identification of Anthrax Receptor CMG2-Fc Fusion Protein in CHO Cell

    Institute of Scientific and Technical Information of China (English)

    郗永义; 胥照平; 高丽华; 邵勇; 胡显文; 陈惠鹏

    2011-01-01

    目的:构建炭疽受体CMG2和人IgG1 Fc片段融合基因载体,转染CHO细胞并通过毒素中和试验检测CMG2-Fc拮抗炭疽毒素(PA+LF)的能力.方法:将含有CMG2胞外区1-217AA片度基因和人IgG1的Fc片段基因共同连接入pcDNA3.1载体转染CHO细胞并筛选高表达CMG2-Fc的CHO细胞系,通过小鼠RAW264.7巨噬细胞保护试验检测 CMG2-Fc拮抗炭疽毒素的能力.结果:获得了表达CMG2-Fc的细胞株,毒素中和实验显示该蛋白可以有效抑制炭疽毒素引起的细胞损伤.结论:CMG2-Fc能够保护小鼠巨噬细胞免受炭疽毒素攻击,提示其可以作为抗毒素治疗炭疽感染.%Objective: To construct fusion gene vector of anthrax receptor CMG2 and human IgG1 Fc fragent, transfect CHO cell and to testify the inhibit ability of CMG2-Fc on anthrax toxin (PA and LF) by toxin neutralization assay.Methods: An expression vector including CMG2 (1-225AA) gene and Fc fragment of human immunoglobulin G (IgG) were constructed, and CHO cell line with higher CMG2-Fc expression were got.The effect of CMG2-Fc on inhibiting anthrax toxin was detected by mouse macrophage protection assay.Result: The CHO cell line expressing CMG2-Fc protein were got, and toxin neutralization assay showed that CMG2-Fc could protect mouse RAW264.7 macrophage cell against anthrax toxins.Conclusion: CMG2-Fc can protect mouse macrophage against anthrax toxin challenge, which indicated that it maybe used as drugs against anthrax in future.

  7. A proteomic study of cMyc improvement of CHO culture

    Directory of Open Access Journals (Sweden)

    Dunn Michael J

    2010-03-01

    Full Text Available Abstract Background The biopharmaceutical industry requires cell lines to have an optimal proliferation rate and a high integral viable cell number resulting in a maximum volumetric recombinant protein product titre. Nutrient feeding has been shown to boost cell number and productivity in fed-batch culture, but cell line engineering is another route one may take to increase these parameters in the bioreactor. The use of CHO-K1 cells with a c-myc plasmid allowing for over-expressing c-Myc (designated cMycCHO gives a higher integral viable cell number. In this study the differential protein expression in cMycCHO is investigated using two-dimensional gel electrophoresis (2-DE followed by image analysis to determine the extent of the effect c-Myc has on the cell and the proteins involved to give the new phenotype. Results Over 100 proteins that were differentially expressed in cMycCHO cells were detected with high statistical confidence, of which 41 were subsequently identified by tandem mass spectrometry (LC-MS/MS. Further analysis revealed proteins involved in a variety of pathways. Some examples of changes in protein expression include: an increase in nucleolin, involved in proliferation and known to aid in stabilising anti-apoptotic protein mRNA levels, the cytoskeleton and mitochondrial morphology (vimentin, protein biosysnthesis (eIF6 and energy metabolism (ATP synthetase, and a decreased regulation of all proteins, indentified, involved in matrix and cell to cell adhesion. Conclusion These results indicate several proteins involved in proliferation and adhesion that could be useful for future approaches to improve proliferation and decrease adhesion of CHO cell lines which are difficult to adapt to suspension culture.

  8. Restriction of human adenovirus replication in Chinese hamster cell lines and their hybrids with human cells.

    Science.gov (United States)

    Radna, R L; Foellmer, B; Feldman, L A; Francke, U; Ozer, H L

    1987-11-01

    We have found that the replication of human adenovirus (Ad2) is restricted in multiple Chinese hamster cell lines including CHO and V79. The major site of restriction involves differential accumulation of late viral proteins as demonstrated by immunofluorescence assay and polyacrylamide gel electrophoresis with and without prior immunoprecipitation. Synthesis of fiber and penton base are markedly reduced, whereas others, such as the 100K polypeptide, are synthesized efficiently. This pattern of restriction is similar to that previously reported for Ad2 infection of several monkey cell lines; however, the restriction is more marked in the Chinese hamster cell lines. The restriction is most likely due to a deficient cellular function since stable cell hybrids between V79 or CHO and human cells are permissive for virus replication. By analysis of a series of hybrids with reduced numbers of human chromosomes, fiber synthesis was correlated with the presence of the short arm of human chromosome 3. More hybrids showed restoration of fiber synthesis than production of progeny virus, suggesting that more than one unlinked function is required for the latter.

  9. Effects of toluene exposure on signal transduction: toluene reduced the signaling via stimulation of human muscarinic acetylcholine receptor m2 subtypes in CHO cells.

    Science.gov (United States)

    Tsuga, Hirofumi; Haga, Tatsuya; Honma, Takeshi

    2002-07-01

    The organic solvent toluene is used widely in industry and is toxic to the central nervous system (CNS). To clarify the mechanisms of CNS toxicity following toluene exposure, especially with respect to the G protein-coupling of receptors, we determined the effects of toluene on the activation of Gi by stimulating human muscarinic acetylcholine receptor m2 subtypes (hm2 receptors) expressed in Chinese hamster ovary (CHO) cells. We first examined whether toluene affects the inhibition of adenylyl cyclase by Gi. The attenuation of forskolin-stimulated cAMP formation by the stimulation of hm2 receptors was reduced in a medium containing toluene. Next, we determined the effects of toluene on carbamylcholine-stimulated [35S]GTPgammaS binding using membrane fractions of CHO cell expressing hm2 receptors. Carbamylcholine-stimulated [35S]GTPgammaS binding activity was markedly reduced when assayed using reaction buffers containing toluene. However, carbamylcholine-stimulated [35S]GTPgammaS binding activity was essentially unchanged following pretreatment of the cells with a toluene-saturated medium prior to membrane isolation. Toluene pretreatment and the toluene itself did not alter the characteristics of the binding of carbamylcholine and [3H]N-methylscopolamine to hm2 receptors. On the contrary of the effect of toluene for [35S]GTPgammaS binding, the effect of toluene for attenuation of forskolin-stimulated cAMP formation by the stimulation of hm2 receptors was irreversible. These observations indicate that toluene acts as an inhibitor of the signal transduction via hm2 receptor stimulation in CHO cells, and at least two mechanisms exist in the inhibition mechanisms by toluene.

  10. The Protective Effect of Rosemary Acid on DNA Damage of CHO Cells%迷迭香酸对CHO细胞DNA损伤的防护作用

    Institute of Scientific and Technical Information of China (English)

    夭建华; 高茜; 李雪梅; 黄海涛; 管莹; 米其利; 罗瑛

    2016-01-01

    采用高内涵分析技术测定DNA损伤/双键断裂的标志物γH2AX,来研究迷迭香酸对细胞DNA损伤的防护作用。即通过在体外对CHO细胞施予迷迭香酸,再诱导DNA损伤,对致损后的细胞进行γH2AX及Hoechst双荧光染色标记,最后通过分析γH2AX的荧光强度从而对细胞DNA损伤程度进行半定量检测。结果发现,施予迷迭香酸的细胞与对照相比较,DNA损伤程度降低,表明迷迭香酸对CHO细胞的DNA损伤具有防护作用。%To investigate the protective effect of rosemary acid on DNA damage,the DNA damage/double strand breaks biomarkerγH2AX was detected by using high content analysis technique. CHO cells were treated with rosemary acid, and then DNA damage was induced. Cells were double staining withγH2AX and Hoechst, andfinally the obtainedfluorescence intensity ofγH2AX was used to semi - quantitatively characterize the degree of DNA damage. The results showed that comparing with the control, CHO cells treated with rosemary acid had a lower degree of DNA damage, which indicated that the rosemary acid had protective effect on the DNA damage of CHO cells.

  11. Effect of scavengers of active oxygen species on cell damage caused in CHO-K1 cells by phenylhydroquinone, an o-phenylphenol metabolite.

    Science.gov (United States)

    Tayama, S; Nakagawa, Y

    1994-07-01

    Phenylhydroquinone (PHQ), a metabolite of o-phenylphenol (OPP), is easily autoxidized to phenylbenzoquinone (PBQ) via the semiquinone (phenylsemiquinone, PSQ) with concomitant production of superoxide anion radicals (O2-.). We have used scavengers of active oxygen species to examine whether or not O2-. produced during oxidation of PHQ is related to cell damage in CHO-K1 cells. PHQ at 10 micrograms/ml (3-h treatment) induced sister-chromatid exchange (SCE), endoreduplication (ERD) and cell-cycle delay in CHO-K1 cells. These effects were inhibited by catalase (280 U/ml), a scavenger of hydrogen peroxide (H2O2), as well as by the reductants, ascorbate (3 mM) and GSH (1 mM). Mannitol (50 mM), a scavenger of hydroxyl radical (OH.), was ineffective and superoxide dismutase (SOD, 150 U/ml), a scavenger of O2-., or SOD plus catalase rather intensified the toxicity as did aminotriazole (20 mM), an inhibitor of catalase. Analyses of incubation solutions by HPLC showed that the extent of cell damage is correlated with PHQ loss; catalase suppressed PHQ loss, whereas SOD promoted it. The correlation was more clearly seen in the time courses of cell death and PHQ loss during incubation of PHQ with each of the scavengers of active oxygen species. These results show that neither O2-. nor OH. participates in the cell damage, but rather H2O2 generated via dismutation of O2-. may participate, probably by accelerating the autoxidation of PHQ and thus causing an increase in the production of toxic intermediates. In fact, conversion of PHQ to PBQ, a reactive product, was demonstrated during incubation with PHQ in phosphate-buffered saline by following the changes in UV-visible spectra of PHQ. Inclusion of H2O2 (0.2 or 1 mM) in the incubation mixture accelerated the PHQ loss. The present results can be explained in terms of the autoxidation mechanism of hydroquinone proposed by O'Brien (1991). Different from the results in the absence of S9 mix, the cell damage induced by 50 micrograms

  12. Quantitative modeling of viable cell density, cell size, intracellular conductivity, and membrane capacitance in batch and fed-batch CHO processes using dielectric spectroscopy.

    Science.gov (United States)

    Opel, Cary F; Li, Jincai; Amanullah, Ashraf

    2010-01-01

    Dielectric spectroscopy was used to analyze typical batch and fed-batch CHO cell culture processes. Three methods of analysis (linear modeling, Cole-Cole modeling, and partial least squares regression), were used to correlate the spectroscopic data with routine biomass measurements [viable packed cell volume, viable cell concentration (VCC), cell size, and oxygen uptake rate (OUR)]. All three models predicted offline biomass measurements accurately during the growth phase of the cultures. However, during the stationary and decline phases of the cultures, the models decreased in accuracy to varying degrees. Offline cell radius measurements were unsuccessfully used to correct for the deviations from the linear model, indicating that physiological changes affecting permittivity were occurring. The beta-dispersion was analyzed using the Cole-Cole distribution parameters Deltaepsilon (magnitude of the permittivity drop), f(c) (critical frequency), and alpha (Cole-Cole parameter). Furthermore, the dielectric parameters static internal conductivity (sigma(i)) and membrane capacitance per area (C(m)) were calculated for the cultures. Finally, the relationship between permittivity, OUR, and VCC was examined, demonstrating how the definition of viability is critical when analyzing biomass online. The results indicate that the common assumptions of constant size and dielectric properties used in dielectric analysis are not always valid during later phases of cell culture processes. The findings also demonstrate that dielectric spectroscopy, while not a substitute for VCC, is a complementary measurement of viable biomass, providing useful auxiliary information about the physiological state of a culture.

  13. Effects of Saponins against Clinical E. coli Strains and Eukaryotic Cell Line

    Directory of Open Access Journals (Sweden)

    Michał Arabski

    2012-01-01

    Full Text Available Saponins are detergent-like substances showing antibacterial as well as anticancer potential. In this study, the effects of saponins from Quillaja saponaria were analyzed against prokaryotic and eukaryotic cells. Multidrug-resistant clinical E. coli strains were isolated from human urine. As eukaryotic cells, the CHO-K1 cell lines were applied. Antibacterial effect of ampicillin, streptomycin, and ciprofloxacin in the presence of saponins was measured by cultivation methods. Properties of saponins against CHO-K1 cells were measured by the MTT test, hemolysis assay and flow cytometry. Saponin from Quillaja saponaria has a cytotoxic effect at concentrations higher than 25 μg/mL and in the range of 12–50 μg/mL significantly increases the level of early apoptotic cells. Saponin at dose of 12 μg/mL enhances the six E. coli strains growth. We postulate that saponins increase the influx of nutrients from the medium into E. coli cells. Saponins do not have synergetic effects on antibacterial action of tested antibiotics. In contrary, in the presence of saponins and antibiotics, more CFU/mL E. coli cells were observed. This effect was similar to saponins action alone towards E. coli cells. In conclusion, saponins was cytotoxic against CHO-K1 cells, whereas against E. coli cells this effect was not observed.

  14. Efficient production of sTNFRII-gAD fusion protein in large quantity by use of the modified CHO-S cell expression system.

    Directory of Open Access Journals (Sweden)

    Qinzhen Cai

    Full Text Available TNFα is one of the initial and important mediators to activate downstream signaling pathways by binding to trimerized TNFα receptors (TNFR, and thus is an ideal drug target for cancer therapy. Taking advantage of intrinsic homotimerization of the globular domain of adiponectin (gAD, we have developed a novel TNFα antagonist, the trimerized fusion protein named sTNFRII-gAD. However, our previously-used CHO expression system yielded less than 10 mg/L of sTNFRII-gAD. To produce large quantities of sTNFRII-gAD efficiently, we used a modified CHO-S cell expression system, which is based on a pMH3 vector with non-coding GC-rich DNA fragments for high-level gene expression. We obtained stable clones that produced 75 mg/L of sTNFRII-gAD in the 96-well plate, adapted the clones to 40 ml suspension serum-free batch culture, then optimized the culturing conditions to scale up the fed-batch culture in a 3 L shake-flask and finally in a 5 L AP30 bioreactor. We achieved a final yield of 52 mg/L of sTNFRII-gAD. The trimerized sTNFRII-gAD exhibited the higher affinity to TNFα with a dissociation constant (Kd of 5.63 nM than the dimerized sTNFRII-Fc with a Kd of 13.4 nM, and further displayed the higher TNFα-neutralizing activity than sTNFRII-Fc (p<0.05 in a L929 cytotoxicity assay. Therefore, the strategy employed in this study may provide an efficient avenue for large-scale production of other recombinant proteins by use of the modified CHO-S cell expression system.

  15. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian

    2015-01-01

    and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards...... optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylationrelated product quality. In this work, different fed-batch processes with two chemically defined proprietary media...

  16. A multi-pronged investigation into the effect of glucose starvation and culture duration on fed-batch CHO cell culture

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian;

    2015-01-01

    In this study, omics-based analysis tools were used to explore the effect of glucose starvation and culture duration on monoclonal antibody (mAb) production in fed-batch CHO cell culture to gain better insight into how these parameters can be controlled to ensure optimal mAb productivity and qual......In this study, omics-based analysis tools were used to explore the effect of glucose starvation and culture duration on monoclonal antibody (mAb) production in fed-batch CHO cell culture to gain better insight into how these parameters can be controlled to ensure optimal mAb productivity...... and quality. Titer and N-glycosylation of mAbs, as well as proteomic signature and metabolic status of the production cells in the culture were assessed. We found that the impact of glucose starvation on the titer and N-glycosylation of mAbs was dependent on the degree of starvation during early stationary...... phase of the fed-batch culture. Higher degree of glucose starvation reduced intracellular concentrations of UDP-GlcNAc and UDP-GalNAc, but increased the levels of UDP-Glc and UDP-Gal. Increased GlcNAc and Gal occupancy correlated well with increased degree of glucose starvation, which can be attributed...

  17. DNA display selection of peptide ligands for a full-length human G protein-coupled receptor on CHO-K1 cells.

    Directory of Open Access Journals (Sweden)

    Nobuhide Doi

    Full Text Available The G protein-coupled receptors (GPCRs, which form the largest group of transmembrane proteins involved in signal transduction, are major targets of currently available drugs. Thus, the search for cognate and surrogate peptide ligands for GPCRs is of both basic and therapeutic interest. Here we describe the application of an in vitro DNA display technology to screening libraries of peptide ligands for full-length GPCRs expressed on whole cells. We used human angiotensin II (Ang II type-1 receptor (hAT1R as a model GPCR. Under improved selection conditions using hAT1R-expressing Chinese hamster ovary (CHO-K1 cells as bait, we confirmed that Ang II gene could be enriched more than 10,000-fold after four rounds of selection. Further, we successfully selected diverse Ang II-like peptides from randomized peptide libraries. The results provide more precise information on the sequence-function relationships of hAT1R ligands than can be obtained by conventional alanine-scanning mutagenesis. Completely in vitro DNA display can overcome the limitations of current display technologies and is expected to prove widely useful for screening diverse libraries of mutant peptide and protein ligands for receptors that can be expressed functionally on the surface of CHO-K1 cells.

  18. Optimization protein productivity of human interleukin-2 through codon usage, gene copy number and intracellular tRNA concentration in CHO cells.

    Science.gov (United States)

    Ou, Kua-Chun; Wang, Chih-Yang; Liu, Kuan-Ting; Chen, Yi-Ling; Chen, Yi-Chen; Lai, Ming-Derg; Yen, Meng-Chi

    2014-11-14

    Transfer RNA (tRNA) abundance is one of the critical factors for the enhancement of protein productivity in prokaryotic and eukaryotic hosts. Gene copy number of tRNA and tRNA codon usage bias are generally used to match tRNA abundance of protein-expressing hosts and to optimize the codons of recombinant proteins. Because sufficient concentration of intracellular tRNA and optimized codons of recombinant proteins enhanced translation efficiency, we hypothesized that sufficient supplement of host's tRNA improved protein productivity in mammalian cells. First, the small tRNA sequencing results of CHO-K1 cells showed moderate positive correlation with gene copy number and codon usage bias. Modification of human interleukin-2 (IL-2) through codons with high gene copy number and high codon usage bias (IL-2 HH, modified on Leu, Thr, Glu) significantly increased protein productivity in CHO-K1 cells. In contrast, modification through codons with relatively high gene copy number and low codon usage bias (IL-2 HL, modified on Ala, Thr, Val), or relatively low gene copy number and low codon usage bias (IL-2 LH, modified on Ala, Thr, Val) did not increase IL-2 productivity significantly. Furthermore, supplement of the alanine tRNA or threonine tRNA increased IL-2 productivity of IL-2 HL. In summary, we revealed a potential strategy to enhance productivity of recombinant proteins, which may be applied in production of protein drug or design of DNA vaccine.

  19. Endoplasmic Reticulum-Associated rht-PA Processing in CHO Cells: Influence of Mild Hypothermia and Specific Growth Rates in Batch and Chemostat Cultures.

    Directory of Open Access Journals (Sweden)

    Mauricio Vergara

    Full Text Available Chinese hamster ovary (CHO cells are the main host for producing recombinant proteins with human therapeutic applications mainly because of their capability to perform proper folding and glycosylation processes. In addition, mild hypothermia is one of the main strategies for maximising the productivity of these systems. However, little information is available on the effect of culture temperature on the folding and degradation processes of recombinant proteins that takes place in the endoplasmic reticulum.In order to evaluate the effect of the mild hypothermia on processing/endoplasmatic reticulum-associated degradation (ERAD processes, batch cultures of CHO cells producing recombinant human tissue plasminogen activator (rht-PA were carried out at two temperatures (37°C and 33°C and treated with specific inhibitors of glycosylation and ERAD I (Ubiquitin/Proteasome system or ERAD II (Autophagosoma/Lisosomal system pathways. The effect of mild hypothermia was analysed separately from its indirect effect on specific cell growth rate. To do this, chemostat cultures were carried out at the same incubation conditions as the batch cultures, controlling cell growth at high (0.017 h-1 and low (0.012 h-1 dilution rates. For a better understanding of the investigated phenomenon, cell behaviour was also analysed using principal component analysis (PCA.Results suggest that rht-PA is susceptible to degradation by both ERAD pathways studied, revealing that processing and/or ERAD processes are sensitive to temperature cultivation in batch culture. Moreover, by isolating the effect of culture temperature from the effect of cell growth rate verifyed by using chemostat cultures, we have found that processing and/or ERAD processes are more sensitive to reduction in specific growth rate than low temperature, and that temperature reduction may have a positive effect on protein processing. Interestingly, PCA indicated that the integrated performance displayed by CHO

  20. Fast intracellular dissolution and persistent cellular uptake of silver nanoparticles in CHO-K1 cells: implication for cytotoxicity.

    Science.gov (United States)

    Jiang, Xiumei; Miclăuş, Teodora; Wang, Liming; Foldbjerg, Rasmus; Sutherland, Duncan S; Autrup, Herman; Chen, Chunying; Beer, Christiane

    2015-03-01

    Toxicity of silver nanoparticles (Ag NPs) has been reported both in vitro and in vivo. However, the intracellular stability and chemical state of Ag NPs are still not very well studied. In this work, we systematically investigated the cellular uptake pathways, intracellular dissolution and chemical species, and cytotoxicity of Ag NPs (15.9 ± 7.6 nm) in Chinese hamster ovary cell subclone K1 cells, a cell line recommended by the OECD for genotoxicity studies. Quantification of intracellular nanoparticle uptake and ion release was performed through inductively coupled plasma mass spectrometry. X-ray absorption near-edge structure (XANES) was employed to assess the chemical state of intracellular silver. The toxic potential of Ag NPs and Ag(+) was evaluated by cell viability, reactive oxygen species (ROS) production and live-dead cell staining. The results suggest that cellular uptake of Ag NPs involves lipid-raft-mediated endocytosis and energy-independent diffusion. The degradation study shows that Ag NPs taken up into cells dissolved quickly and XANES results directly indicated that the internalized Ag was oxidized to Ag-O- species and then stabilized in silver-sulfur (Ag-S-) bonds within the cells. Subsequent cytotoxicity studies show that Ag NPs decrease cell viability and increase ROS production. Pre-incubation with N-acetyl-L-cysteine, an efficient antioxidant and Ag(+) chelator, diminished the cytotoxicity caused by Ag NPs or Ag(+) exposure. Our study suggests that the cytotoxicity mechanism of Ag NPs is related to the intracellular release of silver ions, followed by their binding to SH-groups, presumably coming from amino acids or proteins, and affecting protein functions and the antioxidant defense system of cells.

  1. Modeling of cell culture damage and recovery leads to increased antibody and biomass productivity in CHO cell cultures.

    Science.gov (United States)

    Naderi, Saeideh; Nikdel, Ali; Meshram, Mukesh; McConkey, Brendan; Ingalls, Brian; Budman, Hector; Scharer, Jeno

    2014-09-01

    The development of an efficient and productive cell-culture process requires a deep understanding of intracellular mechanisms and extracellular conditions for optimal product synthesis. Mathematical modeling provides an effective strategy to predict, control, and optimize cell performance under a range of culture conditions. In this study, a mathematical model is proposed for the investigation of cell damage of a Chinese hamster ovary cell culture secreting recombinant anti-RhD monoclonal antibody (mAb). Irreversible cell damage was found to be correlated with a reduction in pH. This irreversible damage to cellular function is described mathematically by a Tessier-based model, in which the actively growing fraction of cells is dependent on an intracellular metabolic product acting as a growth inhibitor. To further verify the model, an offline model-based optimization of mAb production in the cell culture was carried out, with the goal of minimizing cell damage and thereby enhancing productivity through intermittent refreshment of the culture medium. An experimental implementation of this model-based strategy resulted in a doubling of the yield as compared to the batch operation and the resulting biomass and productivity profiles agreed with the model predictions.

  2. A multi-pronged investigation into the effect of glucose starvation and culture duration on fed-batch CHO cell culture.

    Science.gov (United States)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Lund, Anne Mathilde; Sen, Jette Wagtberg; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Baycin-Hizal, Deniz; Betenbaugh, Michael J; Weilguny, Dietmar; Andersen, Mikael Rørdam

    2015-10-01

    In this study, omics-based analysis tools were used to explore the effect of glucose starvation and culture duration on monoclonal antibody (mAb) production in fed-batch CHO cell culture to gain better insight into how these parameters can be controlled to ensure optimal mAb productivity and quality. Titer and N-glycosylation of mAbs, as well as proteomic signature and metabolic status of the production cells in the culture were assessed. We found that the impact of glucose starvation on the titer and N-glycosylation of mAbs was dependent on the degree of starvation during early stationary phase of the fed-batch culture. Higher degree of glucose starvation reduced intracellular concentrations of UDP-GlcNAc and UDP-GalNAc, but increased the levels of UDP-Glc and UDP-Gal. Increased GlcNAc and Gal occupancy correlated well with increased degree of glucose starvation, which can be attributed to the interplay between the dilution effect associated with change in specific productivity of mAbs and the changed nucleotide sugar metabolism. Herein, we also show and discuss that increased cell culture duration negatively affect the maturation of glycans. In addition, comparative proteomics analysis of cells was conducted to observe differences in protein abundance between early growth and early stationary phases. Generally higher expression of proteins involved in regulating cellular metabolism, extracellular matrix, apoptosis, protein secretion and glycosylation was found in early stationary phase. These analyses offered a systematic view of the intrinsic properties of these cells and allowed us to explore the root causes correlating culture duration with variations in the productivity and glycosylation quality of monoclonal antibodies produced with CHO cells.

  3. CHO(E)P-14 followed by alemtuzumab consolidation in untreated peripheral T cell lymphomas: final analysis of a prospective phase II trial.

    Science.gov (United States)

    Binder, C; Ziepert, M; Pfreundschuh, M; Dührsen, U; Eimermacher, H; Aldaoud, A; Rosenwald, A; Loeffler, M; Schmitz, N; Truemper, L

    2013-11-01

    The rate of long-term remissions after treatment of peripheral T cell lymphomas (PTCL) with standard CHOP-like protocols is unsatisfactory. A prospective multicenter phase II trial was initiated in untreated patients with PTCL of all International Prognostic Index-risk groups, evaluating alemtuzumab consolidation in patients with complete or good partial remission after CHO(E)P-14 induction. Twenty-nine (70.7 %) of the 41 enrolled patients received alemtuzumab consolidation (133 mg in total). The main grades 3-4 toxicities during alemtuzumab therapy were infections and neutropenia with one potentially treatment-related death. Complete responses were seen in 58.5 %, partial responses in 2.4 % and 29.3 % had progressive disease. After a median observation time of 46 months, 19 patients have died, 16 of them due to lymphoma and/or salvage therapy complications. Event-free and overall survival at 3 years in the whole intent to treat population are 32.3 and 62.5 %, respectively, and 42.4 and 75.1 % in the patients who received alemtuzumab. In conclusion, application of a short course of alemtuzumab after CHO(E)P-14 induction is feasible although complicated by severe infections. A current phase III trial, applying alemtuzumab as part of the initial chemotherapy protocol to avoid early progression, will further clarify its significance for the therapeutic outcome.

  4. Influence of incorporated bromodeoxyuridine on the induction of chromosomal alterations by ionizing radiation and long-wave UV in CHO cells.

    Science.gov (United States)

    Zwanenburg, T S; van Zeeland, A A; Natarajan, A T

    1985-01-01

    Incorporation of BrdUrd into nuclear DNA sensitizes CHO cells (1) to the induction of chromosomal aberrations by X-rays and 0.5 MeV neutrons and (2) to induction of chromosomal aberrations and SCEs by lw-UV. We have attempted to establish a correlation between induced chromosomal alterations and induced single- or double-strand breaks in DNA. The data show that while DSBs correlate very well with X-ray-induced aberrations, no clear correlation could be established between lw-UV induced SSBs (including alkali-labile sites) and chromosomal alterations. In addition the effect of 3-aminobenzamide (3AB) on the induction of chromosomal aberrations and SCEs induced by lw-UV has been determined. It is shown that 3AB is without any effect when lw-UV-irradiated cells are posttreated with this inhibitor. The significance of these results is discussed.

  5. Landfill leachate sludge use as soil additive prior and after electrocoagulation treatment: A cytological assessment using CHO-k1 cells.

    Science.gov (United States)

    Morozesk, M; Bonomo, M M; Rocha, L D; Duarte, I D; Zanezi, E R L; Jesus, H C; Fernandes, M N; Matsumoto, S T

    2016-09-01

    Electrocoagulation has recently attracted attention as a potential technique for treating toxic effluents due to its versatility and environmental compatibility, generating a residue chemically suitable to be used as a soil additive. In the present study, landfill leachate sludge hazardous effects were investigated prior and after electrocoagulation process using in vitro assays with the mammalian cells CHO-k1. An integrated strategy for risk assessment was used to correctly estimate the possible adverse landfill leachate sludge effects on human health and ecosystem. Electrocoagulation process proved to be an effective treatment due to possibility to improve effluent adverse characteristics and produce sludge with potential to be used as soil additive. Despite low cytoxicity, the residue presented genotoxic and mutagenic effects, indicating a capacity to induce genetic damages, probably due to induction of polyploidization process in cells. The observed effects demand an improvement of waste management methods for reduce negative risks of landfill leachate sludge application.

  6. New cell line development for antibody-producing Chinese hamster ovary cells using split green fluorescent protein

    Directory of Open Access Journals (Sweden)

    Kim Yeon-Gu

    2012-05-01

    Full Text Available Abstract Background The establishment of high producer is an important issue in Chinese hamster ovary (CHO cell culture considering increased heterogeneity by the random integration of a transfected foreign gene and the altered position of the integrated gene. Fluorescence-activated cell sorting (FACS-based cell line development is an efficient strategy for the selection of CHO cells in high therapeutic protein production. Results An internal ribosome entry site (IRES was introduced for using two green fluorescence protein (GFP fragments as a reporter to both antibody chains, the heavy chain and the light chain. The cells co-transfected with two GFP fragments showed the emission of green fluorescence by the reconstitution of split GFP. The FACS-sorted pool with GFP expression had a higher specific antibody productivity (qAb than that of the unsorted pool. The qAb was highly correlated with the fluorescence intensity with a high correlation coefficient, evidenced from the analysis of median GFP and qAb in individual selected clones. Conclusions This study proved that the fragment complementation for split GFP could be an efficient indication for antibody production on the basis of high correlation of qAb with reconstitution of GFP. Taken together, we developed an efficient FACS-based screening method for high antibody-producing CHO cells with the benefits of the split GFP system.

  7. In vitro genotoxic and cytotoxic effects of ivermectin and its formulation ivomec on Chinese hamster ovary (CHO{sub K1}) cells

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, G.; Soloneski, S.; Reigosa, M.A. [Catedra de Citologia, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata (Argentina); Larramendy, M.L., E-mail: m_larramendy@hotmail.com [Catedra de Citologia, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata (Argentina)

    2009-06-15

    The effects of ivermectin (IVM) and its commercial formulation ivomec (IVM 1.0%) were studied on Chinese hamster ovary (CHO{sub K1}) cells by several genotoxicity [sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE)] and cytotoxicity [cell-cycle progression (CCP), mitotic index (MI), proliferative replication index (PRI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR)] bioassays within the 1.0-250 {mu}g/ml concentration-range. While IVM and ivomec did not modified SCE frequencies, they induced DNA-strand breaks revealed by SCGE. An enhancement of slightly damaged cells and a decrease in undamaged cells were observed in IVM-treated cultures with 5.0-50.0 {mu}g/ml. In ivomec-treated cells, while an increase in slightly damaged cells was induced with 5.0-50.0 {mu}g/ml, the damaged and undamaged cells increased and decreased only with 50.0 {mu}g/ml. Both compounds exerted a delay in CCP and a reduction in PRI when 25.0 {mu}g/ml was employed whereas cytotoxicity was observed at higher concentration than 50.0 {mu}g/ml. No MI alteration was observed with 1.0-10.0 and 1.0-5.0 {mu}g/ml of IVM and ivomec, respectively. A concentration-related trend to an increase in MI was achieved within 1.0-10.0 {mu}g/ml. An increase in the MI was induced in 10.0 {mu}g/ml ivomec-treated cultures. A marked reduction of about 89% and 62% in regard to controls was observed with 25.0 {mu}g/ml of IVM and ivomec, respectively. NR and MTT assays revealed a cell growth inhibition when 0.25-250.0 {mu}g/ml of both compounds was employed. The results highlighted that IVM and ivomec exert both genotoxicity and cytotoxicity in mammalian cells in vitro, at least in CHO{sub K1} cells.

  8. Stable expression of mouse IFN-λ2 in CHO cells and its biological activity analysis%鼠IFN-λ2 CHO细胞系建立及生物学活性的研究

    Institute of Scientific and Technical Information of China (English)

    严玉兰; 袁利学; 刘洋; 曹文雁; 步雪峰; 步志高; 郑金旭

    2010-01-01

    目的 稳定表达鼠IFN-λ2并对其生物学活性进行研究.方法 用水疱口炎病毒(vesicular stomatitis virus,VSV)刺激小鼠脾脏细胞,克隆mIFN-λ2全长基因,构建真核表达载体PCAGG-EGFP-mIFN-λ2,并在CHO细胞稳定表达,且在小鼠黑色素瘤B16细胞上进行抗病毒活性测定;构建MDBK-Mxp-Luc细胞系诱导Mx1抗病毒蛋白产生.结果 pMD18-T-mIFN-λ2双酶切鉴定,出现582 bp大小的条带,成功构建了PCAGG-EGFP-mIFN-λ2真核表达载体;稳定表达mIFN-λ2 CHO的细胞株分泌的上清中mIFN-λ2蛋白在B16细胞上的抗病毒活性为10~4 AU/ml;mIFN-λ2蛋白诱导鼠Mx1抗病毒蛋白的表达,9~12 h达高峰,24 h后消失(P<0.05).结论 建立了稳定表达mIFN-λ2的CHO细胞株,其分泌型mIFN-λ2蛋白具有明显的抗病毒活性,且与诱导Mx1抗病毒蛋白密切相关.%Objective To express mouse IFN-λ2 stably and study its biological activity. Methods Full-length of mIFN-λ2 cDNA was obtained by using RT-PCR from cells of mouse spleen stimulated by ve-sicular stomatitis virus(VSV) and then subcloned to eukaryotic expressing vector PCAGG-EGFP. The recom-binant was transfected into CHO cells. VSV * GFP-B16 system was used to measure the antivirus activity. The constructed cell line MDBK-Mxp-Luc was used to study the character of Mx1 protein induced by the mIFN-λ2. Results The recombinant pMD18-T-mIFN-λ2 was digested by two kinds of enzyme, Sac I and Xho I, to produce the fragment was of 582 bp, and of which the sequence analysis of sequence shows it was entirely consistent with the nucleotide sequences reported in GenBank. PCAGG-EGFP-mIFN-λ2 eukaryotic expressing vector was constructed successfully and expressed stably in CHO cells, and the mRNA of mIFN-λ2 was verified expressing in CHO-PCAGG-EGFP-mIFN-λ2 cell line by RT-PCR. The antivirus activity of in the supernatant secreted by the CHO-PCAGG-EGFP-mIFN-λ2 cell line was 10~4 AU/ml. The mIFN-λ2 pro-tein can could induce the expression of

  9. Test for Chemical Induction of Chromosome Aberrations in Cultured Chinese Hamster Ovary (CHO) Cells with and without Metabolic Activation, Test Article: 3-Nitro-1,2,4-Triazol-5-one (NTO)

    Science.gov (United States)

    2008-10-30

    3110 Dicentric - an asymmetrical exchange between two chromosomes resulting in a chromosome with two centromeres with or without an accompanying...chromatid union. Dicentric - an asymmetrical exchange between two chromosomes resulting in a chromosome with two centromeres with or without an...Test for Chemical fuduction of Chromosome Aberrations in Cultured Chinese Hamster Ovary (CHO) Cells With and Without Metabolic Activation Test

  10. CD147 overexpression promotes tumorigenicity in Chinese hamster ovary cells.

    Science.gov (United States)

    Yong, Yu-Le; Liao, Cheng-Gong; Wei, Ding; Chen, Zhi-Nan; Bian, Huijie

    2016-04-01

    CD147 overexpresses in many epithelium-originated tumors and plays an important role in tumor migration and invasion. Most studies aim at the role of CD147 in tumor progression using tumor cell models. However, the influence of abnormal overexpression of CD147 on neoplastic transformation of normal cells is unknown. Here, the role of CD147 in malignant phenotype transformation in CHO cells was investigated. Three CHO cell lines that stably overexpressed CD147 (CHO-CD147), EGFP-CD147 (CHO-EGFP-CD147), and EGFP (CHO-EGFP) were generated by transfection of plasmids containing human CD147, EGFP-human CD147, and EGFP genes into CHO cells. Cell migration and invasion were detected by wound healing and transwell matrix penetration assay. Trypan blue exclusion, MTT, cell cycle analysis, and BrdU cell proliferation assay were used to detect cell viability and cell proliferation. Annexin V-FITC analysis was performed to detect apoptosis. We found that CD147 overexpression promoted the migration and invasion of CHO cells. CD147 accelerated the G1 to S phase transition and enhanced the CHO cell proliferation. Overexpression of CD147 inhibited both early- and late-stages of apoptosis of CHO-CD147 cells, which is caused by serum deprivation. CHO-EGFP-CD147 cells showed an increased anchorage-independent growth compared with CHO-EGFP cells as detected by soft-agar colony formation assay. The tumors formed by CHO-CD147 cells in nude mice were larger and coupled with higher expression of proliferating cell nuclear antigen and Ki-67 than that of CHO cells. In conclusion, human CD147 overexpression induces malignant phenotype in CHO cells.

  11. Detailed analysis of the response of different cell lines to carbon irradiation

    CERN Document Server

    Hromcikova, H; Lokajícek, M

    2005-01-01

    Published survival data for Chinese hamster ovarian cells CHO-K1 and their radiosensitive mutant xrs5 after irradiation by carbon ions of energies from 2.4 to 266.4 MeV/u have been analyzed using the probabilistic two-stage radiobiological model, which enables to represent the interplay of damage induction and repair processes. The results give support for the hypothesis that the differences in radiation sensitivity of diverse cell lines are given primarily by their different repair capabilities, and indicate the need for explicitly representing the outcome of repair processes in radiobiological models and treatment planning approaches in radiotherapy.

  12. GM3 alpha2,8-sialyltransferase (GD3 synthase): protein characterization and sub-golgi location in CHO-K1 cells.

    Science.gov (United States)

    Daniotti, J L; Martina, J A; Giraudo, C G; Zurita, A R; Maccioni, H J

    2000-04-01

    GD3 synthase (Sial-T2) is a key enzyme of ganglioside synthesis that, in concert with GM2 synthase (GalNAc-T), regulates the ratio of a- and b-pathway gangliosides. In this work, we study the sub-Golgi location of an epitope-tagged version of chicken Sial-T2 transfected to CHO-K1 cells. The expressed protein was enzymatically active both in vitro and in vivo and showed a molecular mass of approximately 47 or approximately 95 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence or absence of, respectively, beta-mercaptoethanol. The 95-kDa form of Sial-T2 was also detected if the protein was retained in the endoplasmic reticulum (ER) due to impaired glycosylation, indicating that it was formed in the ER. Confocal immunofluorescence microscopy showed Sial-T2 localized to the Golgi complex and, within the organelle, partially co-localizing with the mannose-6-phosphate receptor, a marker of the trans-Golgi network (TGN). In cells treated with brefeldin A, a major fraction of Sial-T2 redistributed to the ER, even under controlled expression to control for mislocalization due to protein overloading. In experiments of incorporation of sugars into endogenous acceptors of Golgi membranes in vitro, GD3 molecules formed by incubation with CMP-NeuAc were converted to GD2 upon incubation with UDP-GalNAc. These results indicate that Sial-T2 localizes mainly to the proximal Golgi, although a fraction is located in the TGN functionally coupled to GalNAc-T. Consistent with this, most of the enzyme was in an endoglycosidase H (Endo-H)-sensitive, neuraminidase (NANase)-insensitive form. A minor secreted form lacking approximately 40 amino acids was Endo-H-resistant and NANase-sensitive, indicating that the cells were able to process N-glycans to Endo-H-resistant forms. Taken together, the results of these biochemical and immunocytochemical experiments indicate that in CHO-K1 cells, most Sial-T2 localizes in the proximal Golgi and that a functional fraction

  13. Evaluation of Cellular Toxicity for Cisplatin, Arsenic And Acetaminophen in the Cancer and Normal Cell Line

    Directory of Open Access Journals (Sweden)

    S Saeedi Saravi

    2007-12-01

    Full Text Available Introduction: Cell culture is a process in which the cells ware isolated from original tissue, dispersed in liquid media and then placed in culture plate where the cells adhere together and propagate. Today, this method is used for assessment of cell toxicity, its mechanisms and effect of different compounds on intracellular components. Methods: Clonogenic assay was used for assessment of cell toxicity and amount of cell death after a specific time during which cells were exposed to different compounds. Thus, IC50 in caner cell lines (HePG2, SKOV3 and A549 and normal cell (LLCPK1, CHO and HGF1 was assessed after exposure to cisplatin, acetaminophen and arsenic. Results: Results showed that acetaminophen has maximum resistance and minimum sensitivity in CHO line with IC50=16.7±1.06 HePG2 with IC50=18.6±1.29. On the other hand, cisplatin showed minimum resistance and maximum sensitivity in HePG2 with IC50 = 0.87±0.07 and HGF1 with IC50 = 1.6±0.21 and lastly, arsenic showed minimum resistance and maximum sensitivity in A549 with IC50 = 4.59±0.29 and LLCPK1 with IC50= 1±0.37. Discussion: According to the evaluated IC50, there were differences between results of sensitivity of cell lines exposed to the three drugs (P<0.05. Entirely, resistance in cancer cell lines was lower than normal cells. The results showed the importance of cell defensive mechanisms encountering different substances like glutathione.

  14. Effect of ethanolic extract of propolis on cell viability of chinese hamster ovary cells (CHO-K1) irradiated with {sup 60}CO gamma-rays using differential staining technique

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marcos P.M. de; Castro, Renato F. de; Okazaki, Kayo; Vieira, Daniel P., E-mail: dpvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of present study was to assess the effect of Brazilian propolis (AF-08) on CHO-K1 cells irradiated with {sup 60}Co, through the differential staining technique, using acridine orange and ethidium bromide. The cells were pre-incubated with different concentrations of propolis (50, 100 and 200 μg/mL) for 24h and irradiated with 5 Gy, analyzed at 24 and 48h after exposure. This technique is based on the cell capacity to incorporate fluorescent DNA dyes, where the viable (green), apoptotic (orange/yellow) and necrotic (red) cells can be identified through fluorescence microscopy. Digital high-resolution images were acquired from at least 5 visualization fields, and cells were analyzed using ImageJ and Flowing software. This approach permitted to analyze a large number of cells/sample with the time reduction, much easier and faster, proportioning more statistical power of the technique. The treatment with propolis only was not cytotoxic at 24 and 48h, except for the higher concentration of 200 μg/mL associated or not with radiation, increasing apoptotic and mainly necrotic cells (p<0.001). The data showed a promising use of propolis as well as technique used, pointing out that 200 μg/mL of propolis was cytotoxic, but at lower one (50 μg/mL) presented a radioprotective effect in irradiated CHO-K1 cells. (author)

  15. Diversity in host clone performance within a Chinese hamster ovary cell line.

    Science.gov (United States)

    O'Callaghan, Peter M; Berthelot, Maud E; Young, Robert J; Graham, James W A; Racher, Andrew J; Aldana, Dulce

    2015-01-01

    Much effort has been expended to improve the capabilities of individual Chinese hamster ovary (CHO) host cell lines to synthesize recombinant therapeutic proteins (rPs). However, given the increasing variety in rP molecular types and formats it may be advantageous to employ a toolbox of CHO host cell lines in biomanufacturing. Such a toolbox would contain a panel of hosts with specific capabilities to synthesize certain molecular types at high volumetric concentrations and with the correct product quality (PQ). In this work, we examine a panel of clonally derived host cell lines isolated from CHOK1SV for the ability to manufacture two model proteins, an IgG4 monoclonal antibody (Mab) and an Fc-fusion protein (etanercept). We show that these host cell lines vary in their relative ability to synthesize these proteins in transient and stable pool production format. Furthermore, we examined the PQ attributes of the stable pool-produced Mab and etanercept (by N-glycan ultra performance liquid chromatography (UPLC) and liquid chromatography - tandem mass spectrometry (LC-MS/MS), respectively), and uncovered substantial variation between the host cell lines in Mab N-glycan micro-heterogeneity and etanercept N and O-linked macro-heterogeneity. To further investigate the capabilities of these hosts to act as cell factories, we examined the glycosylation pathway gene expression profiles as well as the levels of endoplasmic reticulum (ER) and mitochondria in the untransfected hosts. We uncovered a moderate correlation between ER mass and the volumetric product concentration in transient and stable pool Mab production. This work demonstrates the utility of leveraging diversity within the CHOK1SV pool to identify new host cell lines with different performance characteristics.

  16. Pharmacological and functional characterisation of the wild-type and site-directed mutants of the human H1 histamine receptor stably expressed in CHO cells.

    Science.gov (United States)

    Moguilevsky, N; Varsalona, F; Guillaume, J P; Noyer, M; Gillard, M; Daliers, J; Henichart, J P; Bollen, A

    1995-01-01

    A cDNA clone for the human histamine H1 receptor was isolated from a lung cDNA library and stably expressed in CHO cells. The recombinant receptor protein present in the cell membranes, displayed the functional and binding characteristics of histamine H1 receptors. Mutation of Ser155 to Ala in the fourth transmembrane domain did not significantly change the affinity of the receptor for histamine and H1 antagonists. However, mutation of the fifth transmembrane Asn198 to Ala resulted in a dramatic decrease of the affinity for histamine binding, and for the histamine-induced polyphosphoinositides breakdown, whereas the affinity towards antagonists was not significantly modified. In addition, mutation of another fifth transmembrane amino acid, Thr194 to Ala also diminished, but to a lesser extent, the affinity for histamine. These data led us to propose a molecular model for histamine interaction with the human H1 receptor. In this model, the amide moiety of Asn198 and the hydroxyl group of Thr194 are involved in hydrogen bonding with the nitrogen atoms of the imidazole ring of histamine. Moreover, mutation of Thr194 to Ala demonstrated that this residue is responsible for the discrimination between enantiomers of cetirizine.

  17. A multi-pronged investigation into the effect of glucose starvation and culture duration on fed-batch CHO cell culture

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian;

    2015-01-01

    In this study, omics-based analysis tools were used to explore the effect of glucose starvation and culture duration on monoclonal antibody (mAb) production in fed-batch CHO cell culture to gain better insight into how these parameters can be controlled to ensure optimal mAb productivity...... and quality. Titer and N-glycosylation of mAbs, as well as proteomic signature and metabolic status of the production cells in the culture were assessed. We found that the impact of glucose starvation on the titer and N-glycosylation of mAbs was dependent on the degree of starvation during early stationary...... phase of the fed-batch culture. Higher degree of glucose starvation reduced intracellular concentrations of UDP-GlcNAc and UDP-GalNAc, but increased the levels of UDP-Glc and UDP-Gal. Increased GlcNAc and Gal occupancy correlated well with increased degree of glucose starvation, which can be attributed...

  18. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    KAUST Repository

    Hefzi, Hooman

    2016-11-23

    Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways in CHO and associated them with >1,700 genes in the Cricetulus griseus genome. The genome-scale metabolic model based on this reconstruction, iCHO1766, and cell-line-specific models for CHO-K1, CHO-S, and CHO-DG44 cells provide the biochemical basis of growth and recombinant protein production. The models accurately predict growth phenotypes and known auxotrophies in CHO cells. With the models, we quantify the protein synthesis capacity of CHO cells and demonstrate that common bioprocess treatments, such as histone deacetylase inhibitors, inefficiently increase product yield. However, our simulations show that the metabolic resources in CHO are more than three times more efficiently utilized for growth or recombinant protein synthesis following targeted efforts to engineer the CHO secretory pathway. This model will further accelerate CHO cell engineering and help optimize bioprocesses.

  19. The Effect of UDP-glucuronosyltransferase 1A1 Expression on the Mutagenicity and Metabolism of the Cooked-Food Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4-5,b]pyridine in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M A; Wu, R W; Felton, J S

    2004-08-13

    UDP-glucuronosyltransferase proteins (UGT) catalyze the glucuronidation of both endogenous and xenobiotic compounds. In previous studies UGT1A1 has been implicated in the detoxification of certain food-borne-carcinogenic-heterocyclic amines. To determine the importance of UDP-glucuronosyltransferase 1A1 (UGT1A1) in the biotransformation of the cooked-food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), genetically modified CHO cells that are nucleotide excision repair-deficient, and express cytochrome P4501A2 (UV5P3 cell line) were transfected with a cDNA plasmid of human UGT1A1 to establish the UDPglucuronosyltransferase 1A1 expressing 5P3hUGT1A1 cell line. Expression of the UGT1A1 gene was verified by screening neogene expressing clonal isolates (G-418 resistant) for their sensitivity to cell killing from PhIP exposure. Five of eleven clones were chosen for further analysis due to their resistance to cell killing. Western blot analysis was used to confirm the presence of the UGT1A1 and CYP1A2 proteins. All five clones displayed a 52 kDa protein band, which corresponded to a UGT1A1 control protein. Only four of the clones had a protein band that corresponded to the CYP1A2 control protein. Correct fragment size of the cDNAs in the remaining 4 clones was confirmed by RT-PCR and quantification of the mRNA product was accomplished by real-time RT-PCR. Expression of UGT1A1 in the transfected cells was 10{sup 4}-10{sup 5} fold higher relative to the UV5P3 parental cells. One clone (No.14) had a 10 fold higher increase in expression at 1.47 x 10{sup 5} over the other three clones. This clone was also the most active in converting N-hydroxy-PhIP to N-hydroxy-PhIP glucuronide conjugates in microsomal metabolism assays. Based on the D{sub 50} values, the cytotoxic effect of PhIP was decreased {approx}350 fold in the 5P3hUGT1A1 cells compared to the UV5P3 control cells. In addition no significant increase in mutation frequency was observed in the

  20. Molluscan cells in culture: primary cell cultures and cell lines.

    Science.gov (United States)

    Yoshino, T P; Bickham, U; Bayne, C J

    2013-06-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome.

  1. Yellow fluorescent protein-based assay to measure GABA(A channel activation and allosteric modulation in CHO-K1 cells.

    Directory of Open Access Journals (Sweden)

    Teres Johansson

    Full Text Available The γ-aminobutyric acid A (GABA(A ion channels are important drug targets for treatment of neurological and psychiatric disorders. Finding GABA(A channel subtype selective allosteric modulators could lead to new improved treatments. However, the progress in this area has been obstructed by the challenging task of developing functional assays to support screening efforts and the generation of cells expressing functional GABA(A ion channels with the desired subtype composition. To address these challenges, we developed a yellow fluorescent protein (YFP-based assay to be able to study allosteric modulation of the GABA(A ion channel using cryopreserved, transiently transfected, assay-ready cells. We show for the first time how the MaxCyte STX electroporation instrument can be used to generate CHO-K1 cells expressing functional GABA(A α2β3γ2 along with a halide sensing YFP-H148Q/I152L (YFP-GABA(A2 cells. As a basis for a cell-based assay capable of detecting allosteric modulators, experiments with antagonist, ion channel blocker and modulators were used to verify GABA(A subunit composition and functionality. We found that the I(- concentration used in the YFP assay affected both basal quench of YFP and potency of GABA. For the first time the assay was used to study modulation of GABA with 7 known modulators where statistical analysis showed that the assay can distinguish modulatory pEC50 differences of 0.15. In conclusion, the YFP assay proved to be a robust, reproducible and inexpensive assay. These data provide evidence that the assay is suitable for high throughput screening (HTS and could be used to discover novel modulators acting on GABA(A ion channels.

  2. High levels of protein expression using different mammalian CMV promoters in several cell lines.

    Science.gov (United States)

    Xia, Wei; Bringmann, Peter; McClary, John; Jones, Patrick P; Manzana, Warren; Zhu, Ying; Wang, Soujuan; Liu, Yi; Harvey, Susan; Madlansacay, Mary Rose; McLean, Kirk; Rosser, Mary P; MacRobbie, Jean; Olsen, Catherine L; Cobb, Ronald R

    2006-01-01

    With the recent completion of the human genome sequencing project, scientists are faced with the daunting challenge of deciphering the function of these newly found genes quickly and efficiently. Equally as important is to produce milligram quantities of the therapeutically relevant gene products as quickly as possible. Mammalian expression systems provide many advantages to aid in this task. Mammalian cell lines have the capacity for proper post-translational modifications including proper protein folding and glycosylation. In response to the needs described above, we investigated the protein expression levels driven by the human CMV in the presence or absence of intron A, the mouse and rat CMV promoters with intron A, and the MPSV promoter in plasmid expression vectors. We evaluated the different promoters using an in-house plasmid vector backbone. The protein expression levels of four genes of interest driven by these promoters were evaluated in HEK293EBNA and CHO-K1 cells. Stable and transient transfected cells were utilized. In general, the full-length human CMV, in the presence of intron A, gave the highest levels of protein expression in transient transfections in both cell lines. However, the MPSV promoter resulted in the highest levels of stable protein expression in CHO-K1 cells. Using the CMV driven constitutive promoters in the presence of intron A, we have been able to generate >10 microg/ml of recombinant protein using transient transfections.

  3. Targeting the Nuclear Cathepsin L CCAAT Displacement Protein/Cut Homeobox Transcription Factor-Epithelial Mesenchymal Transition Pathway in Prostate and Breast Cancer Cells with the Z-FY-CHO Inhibitor.

    Science.gov (United States)

    Burton, Liza J; Dougan, Jodi; Jones, Jasmine; Smith, Bethany N; Randle, Diandra; Henderson, Veronica; Odero-Marah, Valerie A

    2017-03-01

    The epithelial mesenchymal transition (EMT) promotes tumor migration and invasion by downregulating epithelial markers such as E-cadherin and upregulating mesenchymal markers such as vimentin. Cathepsin L (Cat L) is a cysteine protease that can proteolytically activate CCAAT displacement protein/cut homeobox transcription factor (CUX1). We hypothesized that nuclear Cat L may promote EMT via CUX1 and that this could be antagonized with the Cat L-specific inhibitor Z-FY-CHO. Mesenchymal prostate (ARCaP-M and ARCaP-E overexpressing Snail) and breast (MDA-MB-468, MDA-MB-231, and MCF-7 overexpressing Snail) cancer cells expressed lower E-cadherin activity, higher Snail, vimentin, and Cat L activity, and a p110/p90 active CUX1 form, compared to epithelial prostate (ARCaP-E and ARCaP-Neo) and breast (MCF-7 and MCF-7 Neo) cancer cells. There was increased binding of CUX1 to Snail and the E-cadherin promoter in mesenchymal cells compared to epithelial prostate and breast cells. Treatment of mesenchymal cells with the Cat L inhibitor Z-FY-CHO led to nuclear-to-cytoplasmic relocalization of Cat L, decreased binding of CUX1 to Snail and the E-cadherin promoter, reversed EMT, and decreased cell migration/invasion. Overall, our novel data suggest that a positive feedback loop between Snail-nuclear Cat L-CUX1 drives EMT, which can be antagonized by Z-FY-CHO. Therefore, Z-FY-CHO may be an important therapeutic tool to antagonize EMT and cancer progression.

  4. Bicarbonate concentration and osmolality are key determinants in the inhibition of CHO cell polysialylation under elevated pCO(2) or pH.

    Science.gov (United States)

    Zanghi, J A; Schmelzer, A E; Mendoza, T P; Knop, R H; Miller, W M

    1999-10-20

    Accumulation of CO(2) in animal cell cultures can be a significant problem during scale-up and production of recombinant glycoprotein biopharmaceuticals. By examining the cell-surface polysialic acid (PSA) content, we show that elevated CO(2) partial pressure (pCO(2)) can alter protein glycosylation. PSA is a high-molecular-weight polymer attached to several complex N-linked oligosaccharides on the neural cell adhesion molecule (NCAM), so that small changes in either core glycosylation or in polysialylation are amplified and easily measured. Flow-cytometric analysis revealed that PSA levels on Chinese hamster ovary (CHO) cells decrease with increasing pCO(2) in a dose-dependent manner, independent of any change in NCAM content. The results are highly pH-dependent, with a greater decrease in PSA at higher pH. By manipulating medium pH and pCO(2), we showed that decreases in PSA correlate well with bicarbonate concentration ([HCO(3)(-)]). In fact, it was possible to offset a 60% decrease in PSA content at 120 mm Hg pCO(2) by decreasing the pH from 7.3 to 6.9, such that [HCO(3)(-)] was lowered to that of control (38 mm Hg pCO(2)). When the increase in osmolality associated with elevated [HCO(3)(-)] was offset by decreasing the basal medium [NaCl], elevated [HCO(3)(-)] still caused a decrease in PSA, although less extensive than without osmolality control. By increasing [NaCl], we show that hyperosmolality alone decreases PSA content, but to a lesser extent than for the same osmolality increase due to elevated [NaHCO(3)]. In conclusion, we demonstrate the importance of pH and pCO(2) interactions, and show that [HCO(3)(-)] and osmolality can account for the observed changes in PSA content over a wide range of pH and pCO(2) values.

  5. Assessment of cytotoxic and cytogenetic effects of a 1,2,5-thiadiazole derivative on CHO-K1 cells. Its application as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, C.A. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Mirifico, M.V. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina); Morales, M.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Reigosa, M.A. [IMBICE (Instituto Multidisciplinario de Biologia Celular), CICPBA, CONICET, Calle 526 entre 10 y 11, 1900 La Plata (Argentina); Mele, M. Fernandez Lorenzo de, E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina)

    2009-10-30

    This work focuses on the possible use of phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (TDZ) as a harmless corrosion inhibitor. TDZ range-dose providing minimum adverse effects to the environment and human health, with satisfactory corrosion-inhibiting properties was evaluated. Cytotoxicity and genotoxicity of TDZ at 0.57-12.50 {mu}M concentration range were tested by neutral red, chromosomal aberrations, mitotic index, and colony formation assays. Results showed a significant increase of chromatid-type aberrations for the highest concentration of TDZ assayed (12.50 {mu}M). Additionally, a reduction in the proliferative rate for lower concentrations was detected by the MI assay. We concluded that TDZ should be used at concentrations lower than 1.16 {mu}M. Corrosion assays performed showed good inhibition effect (ca. 50%) at low (0.65 {mu}M) TDZ concentration. Consequently, our results indicated that TDZ induced a time- and dose-dependent genotoxic and cytotoxic response on CHO-K1 cells. Short assays should be complemented with long exposure tests to simulate chronic contact with TDZ since lower threshold levels may be found for shorter exposures and a wrong safety range could be determined.

  6. Calibrated complex impedance of CHO cells and E. coli bacteria at GHz frequencies using scanning microwave microscopy

    Science.gov (United States)

    Tuca, Silviu-Sorin; Badino, Giorgio; Gramse, Georg; Brinciotti, Enrico; Kasper, Manuel; Oh, Yoo Jin; Zhu, Rong; Rankl, Christian; Hinterdorfer, Peter; Kienberger, Ferry

    2016-04-01

    The application of scanning microwave microscopy (SMM) to extract calibrated electrical properties of cells and bacteria in air is presented. From the S 11 images, after calibration, complex impedance and admittance images of Chinese hamster ovary cells and E. coli bacteria deposited on a silicon substrate have been obtained. The broadband capabilities of SMM have been used to characterize the bio-samples between 2 GHz and 20 GHz. The resulting calibrated cell and bacteria admittance at 19 GHz were Y cell = 185 μS + j285 μS and Y bacteria = 3 μS + j20 μS, respectively. A combined circuitry-3D finite element method EMPro model has been developed and used to investigate the frequency response of the complex impedance and admittance of the SMM setup. Based on a proposed parallel resistance-capacitance model, the equivalent conductance and parallel capacitance of the cells and bacteria were obtained from the SMM images. The influence of humidity and frequency on the cell conductance was experimentally studied. To compare the cell conductance with bulk water properties, we measured the imaginary part of the bulk water loss with a dielectric probe kit in the same frequency range resulting in a high level of agreement.

  7. Establishment and Identification of Chinese Hamster Ovary Cell Lines with Stable Expression of Soluble CD40 Ligands

    Directory of Open Access Journals (Sweden)

    JIANG Hua-wei

    2014-09-01

    Full Text Available Objective: To establish the Chinese Hamster Ovary (CHO cell lines with stable expression of soluble CD40 ligands (sCD40L. Methods: Recombinant plasmid pIRES2-EGFP-sCD40L, enzyme digestion and sequencing identification were obtained by cloning sCD40L coding sequences into eukaryotic expression vector pIRES2-EGFP from carrier pDC316-sCD40 containing sCD40L. CHO cells were transfected by electroporation, followed by screening of resistant clones with G418, after which monoclones were obtained by limited dilution assay and multiply cultured. Flow cytometer and reverted fluorescence microscope were applied to observe the expression of green fluorescent protein, while sCD40L expression was detected by polymerase chain reaction (PCR, reverse transcription-polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA from aspects of deoxyribose nucleic acid (DNA, messenger ribonucleic acid (mRNA and protein, respectively. CHO-sCD40L was cultured together with MDA-MB-231 cells to compare the expression changes of surface molecule fatty acid synthase (Fas by flow cytometer and observe the apoptosis of MDA-MB-231 cells after Fas activated antibodies (CH-11 were added 24 h later. Results: Plasmid pIRES2-EGFP-sCD40L was successfully established, and cell lines with stable expression of sCD40L were obtained with cloned culture after CHO cell transfection, which was named as B11. Flow cytometer and reverted fluorescence microscope showed >90% expression of green fluorescent protein, while PCR, RT-PCR and ELISA suggested integration of sCD40L genes into cell genome DNA, transcription of sCD40L mRNA and sCD40L protein expression being (4.5±2.1 ng/mL in the supernatant of cell culture, respectively. After co-culture of B11 and MDA-MB-231 cells, the surface Fas expression of MDA-MB-231 cells was increased from (3±1.02 % to (34.8±8.75%, while the apoptosis rate 24 h after addition of CH11 from (5.4±1.32% to (20.7±5.24%, and the differences

  8. An efficient detection agent for the high throughput screening of recombinant manufacturing cell lines.

    Science.gov (United States)

    Duverger, Valérie; Sauvage, Christophe; Kobr, Michel; Imhof, Markus O

    2013-12-31

    To ensure the selection of high producing recombinant cell lines, a number of screening processes were developed in the presence of detection agents. Here, CHO cell lines secreting recombinant antibodies were detected in semi-solid medium containing detection agents. The aim was to compare two protein A-derived detection agents to two commercial fluorescent antibodies directed against the Fc part of the antibody of interest: the protein A derived Z domain fused to the red fluorescent protein and protein A labelled with a fluorescent Dylight™ 488 dye. All of these agents were compatible with cell recovery and colony formation, and specifically detected colonies secreting recombinant antibodies. Optimisation of the concentration of the fluorescent protein A allowed the identification of a higher number of good producers. Thus these data demonstrate that fluorescently labelled protein A-derivatives can be used for the selection of high producer cells.

  9. Slashing the timelines: Opting to generate high-titer clonal lines faster via viability-based single cell sorting.

    Science.gov (United States)

    Misaghi, Shahram; Shaw, David; Louie, Salina; Nava, Adrian; Simmons, Laura; Snedecor, Brad; Poon, Chungkee; Paw, Jonathan S; Gilmour-Appling, Laurie; Cupp, James E

    2016-01-01

    Chinese hamster ovary (CHO) cell line development (CLD) is a long and laborious process, which requires up to 5 - 6 months in order to generate and bank CHO lines capable of stably expressing therapeutic molecules. Additionally, single cell cloning of these production lines is also necessary to confirm clonality of the production lines. Here we introduce the utilization of viability staining dye in combination with flow cytometer to isolate high titer clones from a pool of selected cells and single cell deposit them into the wells of culture plates. Our data suggests that a stringent selection procedure along with viability dye staining and flow cytometry-based sorting can be used to isolate high expressing clones with titers comparable to that of traditional CLD methods. This approach not only requires less labor and consumables, but it also shortens CLD timelines by at least 3 weeks. Furthermore, single cell deposition of selected cells by a flow sorter can be regarded as an additional clonality assurance factor that in combination with Day 0 imaging can ensure clonality of the production lines.

  10. Bystander effect-induced mutagenicity in HPRT locus of CHO cells following BNCT neutron irradiation: Characteristics of point mutations by sequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kinashi, Yuko [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka (Japan)], E-mail: kinashi@rri.kyoto-u.ac.jp; Suzuki, Minoru; Masunaga, Shinichiro; Ono, Koji [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka (Japan)

    2009-07-15

    To investigate bystander mutagenic effects induced by alpha particles during boron neutron capture therapy (BNCT), we mixed cells that were electroporated with borocaptate sodium (BSH), which led to the accumulation of {sup 10}B inside the cells, with cells that did not contain the boron compound. BSH-containing cells were irradiated with {alpha} particles produced by the {sup 10}B(n,{alpha}){sup 7}Li reaction, whereas cells without boron were only affected by the {sup 1}H(n,{gamma}){sup 2}H and {sup 14}N(n,{rho}){sup 14}C reactions. The frequency of mutations induced in the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus was examined in Chinese hamster ovary (CHO) cells irradiated with neutrons (Kyoto University Research Reactor: 5 MW). Neutron irradiation of 1:1 mixtures of cells with and without BSH resulted in a survival fraction of 0.1, and the cells that did not contain BSH made up 99.4% of the surviving cell population. Using multiplex polymerase chain reactions (PCRs), molecular structural analysis indicated that most of the mutations induced by the bystander effect were point mutations and that the frequencies of total and partial deletions induced by the bystander effect were lower than those resulting from the {alpha} particles produced by the {sup 10}B(n,{alpha}){sup 7}Li reaction or the neutron beam from the {sup 1}H(n,{gamma}){sup 2}H and {sup 14}N(n,{rho}){sup 14}C reactions. The types of point mutations induced by the BNCT bystander effect were analyzed by cloning and sequencing methods. These mutations were comprised of 65.5% base substitutions, 27.5% deletions, and 7.0% insertions. Sequence analysis of base substitutions showed that transversions and transitions occurred in 64.7% and 35.3% of cases, respectively. G:C{yields}T:A transversion induced by 8-oxo-guanine in DNA occurred in 5.9% of base substitution mutants in the BNCT bystander group. The characteristic mutations seen in this group, induced by BNCT {alpha} particles

  11. Impact of Dissolved Oxygen during UV-Irradiation on the Chemical Composition and Function of CHO Cell Culture Media.

    Directory of Open Access Journals (Sweden)

    Sarah M Meunier

    Full Text Available Ultraviolet (UV irradiation is advantageous as a sterilization technique in the biopharmaceutical industry since it is capable of targeting non-enveloped viruses that are typically challenging to destroy, as well as smaller viruses that can be difficult to remove via conventional separation techniques. In this work, we investigated the influence of oxygen in the media during UV irradiation and characterized the effect on chemical composition using NMR and LC-MS, as well as the ability of the irradiated media to support cell culture. Chemically defined Chinese hamster ovary cell growth media was irradiated at high fluences in a continuous-flow UV reactor. UV-irradiation caused the depletion of pyridoxamine, pyridoxine, pyruvate, riboflavin, tryptophan, and tyrosine; and accumulation of acetate, formate, kynurenine, lumichrome, and sarcosine. Pyridoxamine was the only compound to undergo complete degradation within the fluences considered; complete depletion of pyridoxamine was observed at 200 mJ/cm2. Although in both oxygen- and nitrogen-saturated media, the cell culture performance was affected at fluences above 200 mJ/cm2, there was less of an impact on cell culture performance in the nitrogen-saturated media. Based on these results, minimization of oxygen in cell culture media prior to UV treatment is recommended to minimize the negative impact on sensitive media.

  12. Integrated economic and experimental framework for screening of primary recovery technologies for high cell density CHO cultures.

    Science.gov (United States)

    Popova, Daria; Stonier, Adam; Pain, David; Titchener-Hooker, Nigel J; Farid, Suzanne S

    2016-07-01

    Increases in mammalian cell culture titres and densities have placed significant demands on primary recovery operation performance. This article presents a methodology which aims to screen rapidly and evaluate primary recovery technologies for their scope for technically feasible and cost-effective operation in the context of high cell density mammalian cell cultures. It was applied to assess the performance of current (centrifugation and depth filtration options) and alternative (tangential flow filtration (TFF)) primary recovery strategies. Cell culture test materials (CCTM) were generated to simulate the most demanding cell culture conditions selected as a screening challenge for the technologies. The performance of these technology options was assessed using lab scale and ultra scale-down (USD) mimics requiring 25-110mL volumes for centrifugation and depth filtration and TFF screening experiments respectively. A centrifugation and depth filtration combination as well as both of the alternative technologies met the performance selection criteria. A detailed process economics evaluation was carried out at three scales of manufacturing (2,000L, 10,000L, 20,000L), where alternative primary recovery options were shown to potentially provide a more cost-effective primary recovery process in the future. This assessment process and the study results can aid technology selection to identify the most effective option for a specific scenario.

  13. Novel micro-bioreactor high throughput technology for cell culture process development: Reproducibility and scalability assessment of fed-batch CHO cultures.

    Science.gov (United States)

    Amanullah, Ashraf; Otero, Jose Manuel; Mikola, Mark; Hsu, Amy; Zhang, Jinyou; Aunins, John; Schreyer, H Brett; Hope, James A; Russo, A Peter

    2010-05-01

    With increasing timeline pressures to get therapeutic and vaccine candidates into the clinic, resource intensive approaches such as the use of shake flasks and bench-top bioreactors may limit the design space for experimentation to yield highly productive processes. The need to conduct large numbers of experiments has resulted in the use of miniaturized high-throughput (HT) technology for process development. One such high-throughput system is the SimCell platform, a robotically driven, cell culture bioreactor system developed by BioProcessors Corp. This study describes the use of the SimCell micro-bioreactor technology for fed-batch cultivation of a GS-CHO transfectant expressing a model IgG4 monoclonal antibody. Cultivations were conducted in gas-permeable chambers based on a micro-fluidic design, with six micro-bioreactors (MBs) per micro-bioreactor array (MBA). Online, non-invasive measurement of total cell density, pH and dissolved oxygen (DO) was performed. One hundred fourteen parallel MBs (19 MBAs) were employed to examine process reproducibility and scalability at shake flask, 3- and 100-L bioreactor scales. The results of the study demonstrate that the SimCell platform operated under fed-batch conditions could support viable cell concentrations up to least 12 x 10(6) cells/mL. In addition, both intra-MB (MB to MB) as well as intra-MBA (MBA to MBA) culture performance was found to be highly reproducible. The intra-MB and -MBA variability was calculated for each measurement as the coefficient of variation defined as CV (%) = (standard deviation/mean) x 100. The % CV values for most intra-MB and intra-MBA measurements were generally under 10% and the intra-MBA values were slightly lower than those for intra-MB. Cell growth, process parameters, metabolic and protein titer profiles were also compared to those from shake flask, bench-top, and pilot scale bioreactor cultivations and found to be within +/-20% of the historical averages.

  14. Dynamic metabolic flux analysis using B-splines to study the effects of temperature shift on CHO cell metabolism

    Directory of Open Access Journals (Sweden)

    Verónica S. Martínez

    2015-12-01

    Full Text Available Metabolic flux analysis (MFA is widely used to estimate intracellular fluxes. Conventional MFA, however, is limited to continuous cultures and the mid-exponential growth phase of batch cultures. Dynamic MFA (DMFA has emerged to characterize time-resolved metabolic fluxes for the entire culture period. Here, the linear DMFA approach was extended using B-spline fitting (B-DMFA to estimate mass balanced fluxes. Smoother fits were achieved using reduced number of knots and parameters. Additionally, computation time was greatly reduced using a new heuristic algorithm for knot placement. B-DMFA revealed that Chinese hamster ovary cells shifted from 37 °C to 32 °C maintained a constant IgG volume-specific productivity, whereas the productivity for the controls peaked during mid-exponential growth phase and declined afterward. The observed 42% increase in product titer at 32 °C was explained by a prolonged cell growth with high cell viability, a larger cell volume and a more stable volume-specific productivity.

  15. Test for Chemical Induction of Chromosome Aberration in Cultured Chinese Hamster Ovary (CHO) Cells With and Without Metabolic Activation. Test Article: N,N,N’,N’-tetramethyl Ethanediamine (TMEDA)

    Science.gov (United States)

    2008-06-13

    union. d Dicentric - an asymmetrical exchange between two chromosomes resulting in a chromosome with two centromeres with or without an accompanying...Test for Chemical Induction of Chromosome Aberrations in Cultured Chinese Hamster Ovary (CHO) Cells With and Without Metabolic Activation Test...number. 1. REPORT DATE 26 JUN 2008 2. REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE Test for Chemical Induction of Chromosome

  16. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

    OpenAIRE

    Haredy, AM; Nishizawa, A.; Honda, K.; T. Ohya; Ohtake, H; Omasa, T

    2013-01-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host c...

  17. Comparison of internal ribosome entry site (IRES and Furin-2A (F2A for monoclonal antibody expression level and quality in CHO cells.

    Directory of Open Access Journals (Sweden)

    Steven C L Ho

    Full Text Available Four versions of tricistronic vectors expressing IgG1 light chain (LC, IgG1 heavy chain (HC, and dihydrofolate reductase (DHFR in one transcript were designed to compare internal ribosome entry site (IRES and furin-2A (F2A for their influence on monoclonal antibody (mAb expression level and quality in CHO DG44 cells. LC and HC genes are arranged as either the first or the second cistron. When using mAb quantification methods based on the detection antibodies against HC Fc region, F2A-mediated tricistronic vectors appeared to express mAb at higher levels than the IRES-mediated tricistronic vectors in both transient and stable transfections. Further analysis revealed that more than 40% of products detected in stably transfected pools generated using the two F2A-mediated tricistronic vectors were aggregates. LC and HC from the F2A stably transfected pools were not properly processed, giving rise to LC+F2A+HC or HC+F2A+LC fusion proteins, LC and HC polypeptides with F2A remnants, and incorrectly cleaved signal peptides. Both IRES-mediated tricistronic vectors express mAb with correct sizes and signal peptide cleavage. Arrangement of LC as the first cistron in the IRES-mediated tricistronic vectors exhibits increased mAb expression level, better growth, and minimized product aggregation, while arrangement of HC as first cistron results in low expression, slower growth, and high aggregation. The results obtained will be beneficial for designing vectors that enhance mAb expression level and quality in mammalian cells.

  18. Expression of the nfa1 gene cloned from pathogenic Naegleria fowleri in nonpathogenic N. gruberi enhances cytotoxicity against CHO target cells in vitro.

    Science.gov (United States)

    Jeong, Seok-Ryoul; Lee, Sang-Chul; Song, Kyoung-Ju; Park, Sun; Kim, Kyongmin; Kwon, Myung-Hee; Im, Kyung-Il; Shin, Ho-Joon

    2005-07-01

    The pathogenic amoeba Naegleria fowleri has a 360-bp nfa1 gene that encodes the Nfa1 protein (13.1 kDa), which is located in the pseudopodia of the amoeba, and an anti-Nfa1 antibody reduces N. fowleri-induced mammalian-cell cytotoxicity in vitro. In contrast, an anti-Nfa1 antibody cannot detect Nfa1 protein expression in the nonpathogenic amoeba Naegleria gruberi, which also possesses the nfa1 gene. In the present study, the nfa1 gene cloned from pathogenic N. fowleri was transfected into nonpathogenic N. gruberi to determine whether it was related to pathogenicity. The nfa1 gene was initially inserted into a eukaryotic transfection vector, pEGFP-C2, containing a cytomegalovirus promoter and the green fluorescent protein (GFP) gene, and was designed as pEGFP-C2/nfa1UTR (nfa1UTR contains 5' upstream regions, the nfa1 open reading frame, and 3' downstream regions). After transfection, the green fluorescence was observed in the cytoplasm of N. gruberi trophozoites. These transfectants were preserved for more than 9 months after selection. The transfected nfa1 gene was observed by PCR using nfa1- and vector-specific primers in the genomic DNA of N. gruberi transfected with the pEGFP-C2/nfa1UTR vector. In addition, the nfa1 and GFP genes were identified by reverse transcription-PCR in transgenic N. gruberi. The Nfa1 protein expressed in transgenic N. gruberi was identified as a 13.1-kDa band by Western blotting using an anti-Nfa1 antibody. Finally, N. gruberi transfected with the pEGFP-C2/nfa1UTR vector was found to have enhanced cytotoxicity against CHO cells compared with naïve N. gruberi.

  19. An Optimized Method for Suspension Culture of CHO Cells to Produce Recombinant Human Erythropoietin (EPO)%悬浮培养CHO细胞生产重组人促红细胞生成素条件的优化

    Institute of Scientific and Technical Information of China (English)

    杨栋; 牛红军; 陆刚; 史嘉林; 孙浩明; 李晖

    2012-01-01

    Objective: To screen and domesticate the adherent cultured CHO cells to obtain high expression of cell suspension culture for production of recombinant human erythropoietin erythropoietin (rHuEPO). Methods: Using 96-well and 24-well plates culture method to screen and domesticate the highly expressing CHO cell strain. Acclimate the high expression cell strain and make it suitable for suspension culture. It's inoculated into the bioreactor in serum-free culture after amplified by the shake flask, and monitoring of glucose content, measuring rHuEPO expression of daily. Results: The suspension culture of CHO cell production of rHuEPO has short production period, higher expression than adherent culture. On the other hand, it is easy to operate and scale-up, but not easy to pollute. Furthermore, we established of the CHO cell strain for suspension culture,which provided a technical basis for industrial production of CHO cells the rHuEPO. Conclusion: After process optimization, the use of serum-free suspension culture production of erythropoietin average expression has high, short production period, low cost of production.than adherent culture.%目的:通过对贴壁培养CHO细胞筛选驯化,得到高表达的细胞后进行悬浮培养生产重组人促红细胞生成素(rHuEPO).方法:利用96孔板和24孔板对CHO细胞进行筛选,得到高表达细胞株后进行驯化,使其适合悬浮培养,经过摇瓶扩增后接种到生物反应器中无血清培养,每天监测葡萄糖含量,测rHuEPO表达量.结果:悬浮培养CHO细胞生产rHuEPO,生产周期短,表达量比贴壁培养高出很多,操作方便,减少污染,易于放大,并建立了适合悬浮培养的CHO细胞株,为工业化悬浮培养CHO细胞生产rHuEPO提供了技术基础.结论:经过工艺优化后利用无血清悬浮培养生产促红细胞生成素平均表达量较贴壁培养高,生产周期短,有利于降低生产成本.

  20. Generation of a Chinese Hamster Ovary Cell Line Producing Recombinant Human Glucocerebrosidase

    Directory of Open Access Journals (Sweden)

    Juliana Branco Novo

    2012-01-01

    Full Text Available Impaired activity of the lysosomal enzyme glucocerebrosidase (GCR results in the inherited metabolic disorder known as Gaucher disease. Current treatment consists of enzyme replacement therapy by administration of exogenous GCR. Although effective, it is exceptionally expensive, and patients worldwide have a limited access to this medicine. In Brazil, the public healthcare system provides the drug free of charge for all Gaucher’s patients, which reaches the order of $ 84 million per year. However, the production of GCR by public institutions in Brazil would reduce significantly the therapy costs. Here, we describe a robust protocol for the generation of a cell line producing recombinant human GCR. The protein was expressed in CHO-DXB11 (dhfr− cells after stable transfection and gene amplification with methotrexate. As expected, glycosylated GCR was detected by immunoblotting assay both as cell-associated (~64 and 59 kDa and secreted (63–69 kDa form. Analysis of subclones allowed the selection of stable CHO cells producing a secreted functional enzyme, with a calculated productivity of 5.14 pg/cell/day for the highest producer. Although being laborious, traditional methods of screening high-producing recombinant cells may represent a valuable alternative to generate expensive biopharmaceuticals in countries with limited resources.

  1. 极低频磁场联合或不联合X射线对CHO细胞动粒阳性和阴性微核生成的影响%Effects of ELF magnetic fields exposure with or without X-rays on induction of kinetochore positive and negative micronuclei in CHO cells

    Institute of Scientific and Technical Information of China (English)

    DING Guirong; GUO Guozhen

    2005-01-01

    Extremely low frequency magnetic field (ELFMF) produced by power lines and household electric appliances has been associated with increased incidence of cancers, as was suggested by several epidemiological studies[1]. To test the genotoxic effects of ELFMF, the induction of micronuclei by exposure to ELFMF and/or X-rays was investigated by cytokinesis-block method in cultured Chinese Hamster Ovary (CHO) cells. Approximately 4×105 cells were plated in 10cm dishes, following exposure to an ELF magnetic field (60Hz, 5 mT) for 24h. The cells were irradiated to 1 Gy by X-rays. After the irradiation, cytochalasin B was added to the medium at a final concentration of 3 μg / mL. The cells were then exposed to an ELF magnetic field or placed in a normal incubator for 18 h, which is 1.5 times the length of their cell cycle. The micronuclei derived from acentric fragments or from whole chromosomes were evaluated with the help of immunofluorescent staining using antikinetochore antibodies from the serum of scleroderma (CREST syndrome) patients[2,3].Statistically, no significant difference in the frequency of binucleated cells carrying micronuclei was observed between CHO cells cultured in the normal incubator and those placed in the exposure system for 24h. Following X-ray irradiation, the number of binucleated cells carrying micronuclei increased significantly (p< 0.01). Exposure to an ELF magnetic field for 24 h before the X-ray irradiation or for 18 h after X-ray-irradiation did not affect the number of X-ray-induced micronuclei. Among the micronuclei induced by X-ray-irradiation, only a small number were kinetochore-positive (approximately 4 %). The number of kinetochore-positive micronuclei was significantly increased in the cells treated with X-ray irradiation followed by ELFMF exposure or M+X+M treated cells (exposure to ELF magnetic field before and after X-ray irradiation), but not in the cells treated with ELFMF exposure before X-ray irradiation compared with

  2. CHO gene expression profiling in biopharmaceutical process analysis and design.

    Science.gov (United States)

    Schaub, Jochen; Clemens, Christoph; Schorn, Peter; Hildebrandt, Tobias; Rust, Werner; Mennerich, Detlev; Kaufmann, Hitto; Schulz, Torsten W

    2010-02-01

    Increase in both productivity and product yields in biopharmaceutical process development with recombinant protein producing mammalian cells can be mainly attributed to the advancements in cell line development, media, and process optimization. Only recently, genome-scale technologies enable a system-level analysis to elucidate the complex biomolecular basis of protein production in mammalian cells promising an increased process understanding and the deduction of knowledge-based approaches for further process optimization. Here, the use of gene expression profiling for the analysis of a low titer (LT) and high titer (HT) fed batch process using the same IgG producing CHO cell line was investigated. We found that gene expression (i) significantly differed in HT versus LT process conditions due to differences in applied chemically defined, serum-free media, (ii) changed over the time course of the fed batch processes, and that (iii) both metabolic pathways and 14 biological functions such as cellular growth or cell death were affected. Furthermore, detailed analysis of metabolism in a standard process format revealed the potential use of transcriptomics for rational media design as is shown for the case of lipid metabolism where the product titer could be increased by about 20% based on a lipid modified basal medium. The results demonstrate that gene expression profiling can be an important tool for mammalian biopharmaceutical process analysis and optimization.

  3. Selective Modulation of Protein Kinase C α over Protein Kinase C ε by Curcumin and Its Derivatives in CHO-K1 Cells.

    Science.gov (United States)

    Pany, Satyabrata; Majhi, Anjoy; Das, Joydip

    2016-04-12

    Members of the protein kinase C (PKC) family of serine/threonine kinases regulate various cellular functions, including cell growth, differentiation, metabolism, and apoptosis. Modulation of isoform-selective activity of PKC by curcumin (1), the active constituent of Curcuma L., is poorly understood, and the literature data are inconsistent and obscure. The effect of curcumin (1) and its analogues, 4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl oleate (2), (9Z,12Z)-4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl octadeca-9,12-dienoate (3), (9Z,12Z,15Z)-4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl octadeca-9,12,15-trienoate (4), and (1E,6E)-1-[4-(hexadecyloxy)-3-methoxyphenyl]-7-(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione (5), and didemethylcurcumin (6) on the membrane translocation of PKCα, a conventional PKC, and PKCε, a novel PKC, has been studied in CHO-K1 cells, in which these PKC isoforms are endogenously expressed. Translocation of PKC from the cytosol to the membrane was measured using immunoblotting and confocal microscopy. 1 and 6 inhibited the TPA-induced membrane translocation of PKCα but not of PKCε. Modification of the hydroxyl group of curcumin with a long aliphatic chain containing unsaturated double bonds in 2-4 completely abolished this inhibition property. Instead, 2-4 showed significant translocation of PKCα but not of PKCε to the membrane. No membrane translocation was observed with 1, 6, or the analogue 5 having a saturated long chain for either PKCα or PKCε. 1 and 6 inhibited TPA-induced activation of ERK1/2, and 2-4 activated it. ERK1/2 is the downstream readout of PKC. These results show that the hydroxyl group of curcumin is important for PKC activity and the curcumin template can be useful in developing isoform specific PKC modulators for regulating a particular disease state.

  4. Establishment of Stable High Expression Cell Line with Green Fluorescent Protein and Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shengtao; LIU Wenli; HE Peigen; GONG Feili; YANG Dongliang

    2006-01-01

    In order to establish stable high expression cell lines, the eukaryotic expression vector pIRES2EGFP and recombinant plasmid pIRES2EGFP-TIM-3 were transfected into mammalian cells CHO by Lipofectamine. The transfected cells were cultivated under selective growth medium including G418 and green fluorescent protein (GFP) positive cells were sorted by FACS. Simultaneously, growing transfectants were selected only by G418 in the medium. The GFP expression in stably transfected cells was detected by FACS. Under selective growth conditions with G418, the percentage of GFP positive cells was reduced rapidly and GFP induction was low. In contrast, the percentages of GFP positive cells were increased gradually after FACS. By 3 rounds of GFP selection, the stable high expression cell lines were established. Furthermore, using FACS analysis GFP and the target protein TIM-3 co-expression in the stable transfectants cultured in nonselective medium was detected. Theses results demonstrated that the stably transfected cell lines that express high titer of recombinant protein can be simply and fleetly obtained by using GFP and selective growth medium.

  5. Galsang Cering Climbs Cho Oyu

    Institute of Scientific and Technical Information of China (English)

    XUEWENXIAN

    2004-01-01

    Gongbo is one of the three Chinese mountaineers who climbed Qomolangma, the highest peak of the world, from the northern side for the first time. Nowadays his son, Galsang Cering,last autumn successfully climbed Cho Oyu, which is the world's sixth highest peak at 8.201 meters.

  6. Is Rhodamine 123 an Appropriate Fluorescent Probe to Assess P-Glycoprotein Mediated Multidrug Resistance in Vinblastine-Resistant CHO Cells?

    Directory of Open Access Journals (Sweden)

    Jordi Pétriz

    1997-01-01

    Full Text Available Cellular drug resistance, which involves several mechanisms such as P‐glycoprotein (P‐gp overexpression, kinetic and metabolic quiescence, or the increase in the intracellular levels of glutathione, limits the effectiveness of cancer treatment. It has been reported that functional assessment of the cationic dye rhodamine 123 (Rho123 efflux reveals accurately the drug‐resistant phenotype. To study cellular drug resistance, we have obtained a CHO‐K1 derived cell line resistant to vinblastine by means of multistep selection. This cell line (CHOVBR displays high reactivity with a monoclonal antibody (MAb (C219 directed against an internal domain of P‐gp, and an active Rho123 efflux, as shown by parallel flow cytometric and fluorometric assays. However, under similar experimental conditions, the drug‐sensitive parental cell line CHO‐K1 (as well as the myeloblastic KG1 and KG1a cell lines, was also able to pump Rho123 out. These parental CHO‐K1 cells had a very low reactivity against the C219 Mab, as confirmed by Western blot analysis. Both vinblastine and verapamil inhibited Rho123 efflux in CHO‐K1 cells, but had no effect on CHOVBR cultures. Also, deprivation of vinblastine for one month did not affect Rho123 efflux in these cells. Our results suggest that the activity of P‐gp appears to be essential, but not sufficient to confer drug resistance, and that Rho123‐based functional assays of drug resistance should be evaluated for each cellular experimental model.

  7. Difference in Membrane Repair Capacity Between Cancer Cell Lines and a Normal Cell Line.

    Science.gov (United States)

    Frandsen, Stine Krog; McNeil, Anna K; Novak, Ivana; McNeil, Paul L; Gehl, Julie

    2016-08-01

    Electroporation-based treatments and other therapies that permeabilize the plasma membrane have been shown to be more devastating to malignant cells than to normal cells. In this study, we asked if a difference in repair capacity could explain this observed difference in sensitivity. Membrane repair was investigated by disrupting the plasma membrane using laser followed by monitoring fluorescent dye entry over time in seven cancer cell lines, an immortalized cell line, and a normal primary cell line. The kinetics of repair in living cells can be directly recorded using this technique, providing a sensitive index of repair capacity. The normal primary cell line of all tested cell lines exhibited the slowest rate of dye entry after laser disruption and lowest level of dye uptake. Significantly, more rapid dye uptake and a higher total level of dye uptake occurred in six of the seven tested cancer cell lines (p normal cell line (98 % viable cells) was higher than in the three tested cancer cell lines (81-88 % viable cells). These data suggest more effective membrane repair in normal, primary cells and supplement previous explanations why electroporation-based therapies and other therapies permeabilizing the plasma membrane are more effective on malignant cells compared to normal cells in cancer treatment.

  8. Huh-7 cell line as an alternative cultural model for the production of human like erythropoietin (EPO

    Directory of Open Access Journals (Sweden)

    Kausar Humera

    2011-11-01

    Full Text Available Abstract Background and Aims Erythropoietin (EPO is a glycoprotein hormone which is required to regulate the production of red blood cells. Deficiency of EPO is known to cause anemia in chronically infected renal patients and they require regular blood transfusion. Availability of recombinant EPO has eliminated the need for blood transfusion and now it is extensively used for the treatment of anemia. Glycosylation of erythropoietin is essential for its secretion, stability, protein conformation and biological activity. However, maintenance of human like glycosylation pattern during manufacturing of EPO is a major challenge in biotechnology. Currently, Chinese hamster ovary (CHO cell line is used for the commercial production of erythropoietin but this cell line does not maintain glycosylation resembling human system. With the trend to eliminate non-human constituent from biopharmaceutical products, as a preliminary approach, we have investigated the potential of human hepatoma cell line (Huh-7 to produce recombinant EPO. Materials and methods Initially, the secretory signal and Kozak sequences was added before the EPO mature protein sequence using overlap extension PCR technique. PCR-amplified cDNA fragments of EPO was inserted into mammalian expression vector under the control of the cytomegalovirus (CMV promoter and transiently expressed in CHO and Huh-7 cell lines. After RT-PCR analysis, ELISA and Western blotting was performed to verify the immunochemical properties of secreted EPO. Results Addition of secretory signal and Kozak sequence facilitated the extra-cellular secretion and enhanced the expression of EPO protein. Significant expression (P Conclusion Huh-7 cell line has a great potential to produce glycosylated EPO, suggesting the use of this cell line to produce glycoproteins of the therapeutic importance resembling to the natural human system.

  9. 多孔微载体无血清培养rCHO细胞生产u-PA%Production of u-PA with rCHO Cell Culture on Porous Microcarriers in Serum-free Growth Medium

    Institute of Scientific and Technical Information of China (English)

    胡显文; 肖成祖; 李佐虎; 郭志霞; 高丽华; 张正光; 胥照平; 王菲

    2000-01-01

    在30L搅拌式反应器中无血清培养分泌尿激酶型纤溶酶原激活剂(u-PA)的DNA重组CHO细胞,定期部分更换Cytopore多孔微载体,使生长在多孔微载体中的细胞不断更新繁殖,解决大规模细胞培养中的细胞凋亡问题。在91 d连接换液培养过程中,细胞密度可维持在(1.3~2.6)×107/mL,活细胞比率维持在90%以上。在7.5L搅拌罐中培养细胞,利用外部周期性压力振荡刺激并结合载体更新技术,可减轻密度效应对细胞生长和表达的影响,在一定程度上提高细胞在高密度培养条件下的表达水平。在67 d连续换液培养中,细胞最高密度为2.64×107/mL,活细胞比率维持在95%以上。与稳压操作相比,利用周期变压刺激技术可提高产量10%~20%,且可降低葡萄糖厌氧代谢生成乳酸的转化率,利用4步纯化工艺,从含u-PA约135 g的2100 L上清中获得约80 g u-PA(单链比例约为90%)。%A novel technique was developed to deal with apoptosis in large-scale animal cell culture. By means of replacing part of Cytopore porous microcarriers at regular intervals, a rCHO cell line, which produces urokinase-type plasminogen activitor(u-PA), was cultivated continuously with serum-free medium in a 30L stirred tank for 91 days. The cell density was maintained at (1.3~2.6)×107/mL, and > 90 % of cells was viable. In order to reduce the effect of cell density on cell growth and expression,a cyclic pressure oscillation was exerted on a 7.5L reactor headspace to enhance cell expression at high cell density to a certain extent. During the 67 days of medium-replacement culture, the maximal cell density reached 2.64×107/mL, and cell viability was always kept above 95 % when combined with microcarrier-replacement. Compare to control culture, culture with cyclic pressure oscillation could enhance cell expression level and reduce the ratio of glucose metabolized anaerobically to produce lactate

  10. Dicty_cDB: CHO672 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available iol.tsukuba.ac.jp/CSM/CH/CHO6-C/CHO672Q.Seq.d/ Representative seq. ID - (Link to Original site) Representa...tive DNA sequence >CHO672 (CHO672Q) /CSM/CH/CHO6-C/CHO672Q.Seq.d/ AATAATAAAATAATAAT

  11. Characterization of Chinese Hamster Ovary Cells Producing Coagulation Factor VIII Using Multi-omics Tools

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder

    ,000 fold over the last couple of years due to the revolution of next-generation sequencing (NGS), has dramatically accelerated CHO-omics from virtually non-existent to a vibrant growing field. The aim of this thesis was to investigate the impact of coagulation factor VIII (FVIII) production in CHO cells...... for analysis and engineering of industrially relevant CHO cells. Full implementation of such tools for generating specifically engineered CHO production cell lines may allow significant cost-reductions in production of complex biopharmaceuticals such as FVIII....

  12. False leukemia-lymphoma cell lines: an update on over 500 cell lines.

    Science.gov (United States)

    Drexler, H G; Dirks, W G; Matsuo, Y; MacLeod, R A F

    2003-02-01

    Human leukemia-lymphoma (LL) cell lines represent an extremely important resource for research in a variety of fields and disciplines. As the cell lines are used as in vitro model systems in lieu of primary cell material, it is crucial that the cells in the culture flasks faithfully correspond to the purported objects of study. Obviously, proper authentication of cell line derivation and precise characterization are indispensable requirements to use as model systems. A number of studies has shown an unacceptable level of LL cell lines to be false. We present here the results of authenticating a comprehensively large sample (n = 550) of LL cell lines mainly by DNA fingerprinting and cytogenetic evaluation. Surprisingly, near-identical incidences (ca 15%) of false cell lines were observed among cell lines obtained directly from original investigators (59/395: 14.9%) and from secondary sources (23/155: 14.8%) implying that most cross-contamination is perpetrated by originators, presumably during establishment. By comparing our data with those published, we were further able to subclassify the false cell lines as (1) virtual: cross-contaminated with and unretrievably overgrown by other cell lines during initiation, never enjoying independent existence; (2) misidentified: cross-contaminated subsequent to establishment so that an original prototype may still exist; or (3) misclassified: unwittingly established from an unintended (often normal) cell type. Prolific classic leukemia cell lines were found to account for the majority of cross-contaminations, eg CCRF-CEM, HL-60, JURKAT, K-562 and U-937. We discuss the impact of cross-contaminations on scientific research, the reluctance of scientists to address the problem, and consider possible solutions. These findings provide a rationale for mandating the procurement of reputably sourced LL cell lines and their regular authentication thereafter.

  13. Mapping analysis of scaffold/matrix attachment regions (s/MARs) from two different mammalian cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Pilus, Nur Shazwani Mohd; Ahmad, Azrin; Yusof, Nurul Yuziana Mohd [School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Johari, Norazfa [Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    Scaffold/matrix attachment regions (S/MARs) are potential element that can be integrated into expression vector to increase expression of recombinant protein. Many studies on S/MAR have been done but none has revealed the distribution of S/MAR in a genome. In this study, we have isolated S/MAR sequences from HEK293 and Chinese hamster ovary cell lines (CHO DG44) using two different methods utilizing 2 M NaCl and lithium-3,5-diiodosalicylate (LIS). The isolated S/MARs were sequenced using Next Generation Sequencing (NGS) platform. Based on reference mapping analysis against human genome database, a total of 8,994,856 and 8,412,672 contigs of S/MAR sequences were retrieved from 2M NaCl and LIS extraction of HEK293 respectively. On the other hand, reference mapping analysis of S/MAR derived from CHO DG44 against our own CHO DG44 database have generated a total of 7,204,348 and 4,672,913 contigs from 2 M NaCl and LIS extraction method respectively.

  14. Mapping analysis of scaffold/matrix attachment regions (s/MARs) from two different mammalian cell lines

    Science.gov (United States)

    Pilus, Nur Shazwani Mohd; Johari, Norazfa; Ahmad, Azrin; Yusof, Nurul Yuziana Mohd

    2014-09-01

    Scaffold/matrix attachment regions (S/MARs) are potential element that can be integrated into expression vector to increase expression of recombinant protein. Many studies on S/MAR have been done but none has revealed the distribution of S/MAR in a genome. In this study, we have isolated S/MAR sequences from HEK293 and Chinese hamster ovary cell lines (CHO DG44) using two different methods utilizing 2 M NaCl and lithium-3,5-diiodosalicylate (LIS). The isolated S/MARs were sequenced using Next Generation Sequencing (NGS) platform. Based on reference mapping analysis against human genome database, a total of 8,994,856 and 8,412,672 contigs of S/MAR sequences were retrieved from 2M NaCl and LIS extraction of HEK293 respectively. On the other hand, reference mapping analysis of S/MAR derived from CHO DG44 against our own CHO DG44 database have generated a total of 7,204,348 and 4,672,913 contigs from 2 M NaCl and LIS extraction method respectively.

  15. Virus Discovery Using Tick Cell Lines

    Science.gov (United States)

    Bell-Sakyi, Lesley; Attoui, Houssam

    2016-01-01

    While ticks have been known to harbor and transmit pathogenic arboviruses for over 80 years, the application of high-throughput sequencing technologies has revealed that ticks also appear to harbor a diverse range of endogenous tick-only viruses belonging to many different families. Almost nothing is known about these viruses; indeed, it is unclear in most cases whether the identified viral sequences are derived from actual replication-competent viruses or from endogenous virus elements incorporated into the ticks’ genomes. Tick cell lines play an important role in virus discovery and isolation through the identification of novel viruses chronically infecting such cell lines and by acting as host cells to aid in determining whether or not an entire replication-competent, infective virus is present in a sample. Here, we review recent progress in tick-borne virus discovery and comment on the actual and potential applications for tick cell lines in this emerging research area. PMID:27679414

  16. Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

    Science.gov (United States)

    Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

    2009-01-01

    The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines.

  17. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression.

    Science.gov (United States)

    Haredy, Ahmad M; Nishizawa, Akitoshi; Honda, Kohsuke; Ohya, Tomoshi; Ohtake, Hisao; Omasa, Takeshi

    2013-12-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host cell line. Clone CHO-ATF4-16 did not show any change in growth rate compared with the parental cells or mock-transfected CHO-DP12-SF cells. The expression levels of mRNAs encoding both the antibody heavy and light chains in the CHO-ATF4-16 clone were analyzed. This analysis showed that ATF4 overexpression improved the total production and specific production rate of antibody without affecting the mRNA transcription level. These results indicate that ATF4 overexpression is a promising method for improving recombinant IgG production in CHO cells.

  18. Predicting electroporation of cells in an inhomogeneous electric field based on mathematical modeling and experimental CHO-cell permeabilization to propidium iodide determination.

    Science.gov (United States)

    Dermol, Janja; Miklavčič, Damijan

    2014-12-01

    High voltage electric pulses cause electroporation of the cell membrane. Consequently, flow of the molecules across the membrane increases. In our study we investigated possibility to predict the percentage of the electroporated cells in an inhomogeneous electric field on the basis of the experimental results obtained when cells were exposed to a homogeneous electric field. We compared and evaluated different mathematical models previously suggested by other authors for interpolation of the results (symmetric sigmoid, asymmetric sigmoid, hyperbolic tangent and Gompertz curve). We investigated the density of the cells and observed that it has the most significant effect on the electroporation of the cells while all four of the mathematical models yielded similar results. We were able to predict electroporation of cells exposed to an inhomogeneous electric field based on mathematical modeling and using mathematical formulations of electroporation probability obtained experimentally using exposure to the homogeneous field of the same density of cells. Models describing cell electroporation probability can be useful for development and presentation of treatment planning for electrochemotherapy and non-thermal irreversible electroporation.

  19. Application of Flow Cytometer in CHO Cell Counting and Cell Survival Rate Calculation%应用流式细胞仪进行CHO细胞计数及存活率计算

    Institute of Scientific and Technical Information of China (English)

    高茜; 管莹; 米其利; 李雪梅; 缪明明; 夭建华

    2012-01-01

    Using CHO bioengineering cell as target, application of flow cytometer in cell counting and cell survival rate calculation was explored in this paper. The results showed that cell counting and survival rate calculation could be accurate by the flow cytometer through the set of three parameters SS,EV, and FL3. Compared with blood cell counting plate method, flow cytometer method was more efficient and stable with faster operation and lower SD value. Therefore, to improve the production efficiency and toxicological evaluation reliability, flow cytometer method was recommend to be applied in large scale experiments for cell counting and survival rate calculation.%以CHO生物工程细胞为对象,探索了流式细胞仪在细胞计数和细胞存活率计算方面的应用.通过设定侧向角散射SS、电子体积EV及荧光强度FL3等3个参数,编制CHO细胞计数程序,再应用流式细胞仪进行细胞计数和存活率计算,其结果与血球计数板法基本一致,但操作更迅速、SD值更低,说明流式细胞仪法较血球计数板法更高效稳定.流式细胞仪法提高了生物工程的生产效率和毒理学评价的准确性,可应用于大规模细胞实验中.

  20. HIGH DENSITY CULTIVATION OF A RECOMBINANT CD-1 CELL LINE PRODUCING PROUROKINASE USING A BIOSILON MICROCARRIER CULTURE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    肖成祖; 黄子才; 张正光; 叶建新; 高丽华; 郭智霞; 程度胜; 周鹤山; 孔惟惟

    1994-01-01

    CD-1,a genetically-engineered CHO cell line,was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density(over 1 ×107 cells/ml).Prourokinase was stably secreted at about 180IU/106 cells/24h.Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers,then reattach and proliferate on fresh microcarries.This makes it very easy to scale up production.The microcarries could be reused several times without affecting adhesion ,proliferation and prourokinase secretion.With CM-PECC membrane radial flow chromatography and MPG chromatography,the prouroknase in conditioned medium could be purfied to a specific activity of 1×105IU/mg of protein.The purification factor was about 600 fold,and approxiamately 90% of the biological activity was recovered.

  1. Radiation sensitivity of Merkel cell carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J.H.; Ramsay, J.R.; Birrell, G.W. [Queensland Institute of Medical Research (Australia)] [and others

    1995-07-30

    Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.

  2. Application of (13)C flux analysis to identify high-productivity CHO metabolic phenotypes.

    Science.gov (United States)

    Templeton, Neil; Smith, Kevin D; McAtee-Pereira, Allison G; Dorai, Haimanti; Betenbaugh, Michael J; Lang, Steven E; Young, Jamey D

    2017-01-23

    Industrial bioprocesses place high demands on the energy metabolism of host cells to meet biosynthetic requirements for maximal protein expression. Identifying metabolic phenotypes that promote high expression is therefore a major goal of the biotech industry. We conducted a series of (13)C flux analysis studies to examine the metabolic response to IgG expression during early stationary phase of CHO cell cultures grown in 3L fed-batch bioreactors. We examined eight clones expressing four different IgGs and compared with three non-expressing host-cell controls. Some clones were genetically manipulated to be apoptosis-resistant by expressing Bcl-2Δ, which correlated with increased IgG production and elevated glucose metabolism. The metabolic phenotypes of the non-expressing, IgG-expressing, and Bcl-2Δ/IgG-expressing clones were fully segregated by hierarchical clustering analysis. Lactate consumption and citric acid cycle fluxes were most strongly associated with specific IgG productivity. These studies indicate that enhanced oxidative metabolism is a characteristic of high-producing CHO cell lines.

  3. Stem cell characteristics in prostate cancer cell lines.

    NARCIS (Netherlands)

    Pfeiffer, M.J.; Schalken, J.A.

    2010-01-01

    BACKGROUND: Recent studies indicate the presence of a small, stem-like cell population in several human cancers that is crucial for the tumour (re)population. OBJECTIVE: Six established prostate cancer (PCa) cell lines-DU145, DuCaP, LAPC-4, 22Rv1, LNCaP, and PC-3-were examined for their stem cell pr

  4. Increased recombinant protein production owing to expanded opportunities for vector integration in high chromosome number Chinese hamster ovary cells.

    Science.gov (United States)

    Yamano, Noriko; Takahashi, Mai; Ali Haghparast, Seyed Mohammad; Onitsuka, Masayoshi; Kumamoto, Toshitaka; Frank, Jana; Omasa, Takeshi

    2016-08-01

    Chromosomal instability is a characteristic of Chinese hamster ovary (CHO) cells. Cultures of these cells gradually develop heterogeneity even if established from a single cell clone. We isolated cells containing different numbers of chromosomes from a CHO-DG44-based human granulocyte-macrophage colony stimulating factor (hGM-CSF)-producing cell line and found that high chromosome number cells showed higher hGM-CSF productivity. Therefore, we focused on the relationship between chromosome aneuploidy of CHO cells and high recombinant protein-producing cell lines. Distribution and stability of chromosomes were examined in CHO-DG44 cells, and two cell lines expressing different numbers of chromosomes were isolated from the original CHO-DG44 cell line to investigate the effect of aneuploid cells on recombinant protein production. Both cell lines were stably transfected with a vector that expresses immunoglobulin G3 (IgG3), and specific antibody production rates were compared. Cells containing more than 30 chromosomes had higher specific antibody production rates than those with normal chromosome number. Single cell analysis of enhanced green fluorescent protein (Egfp)-gene transfected cells revealed that increased GFP expression was relative to the number of gene integration sites rather than the difference in chromosome numbers or vector locations. Our results suggest that CHO cells with high numbers of chromosomes contain more sites for vector integration, a characteristic that could be advantageous in biopharmaceutical production.

  5. Cellular radiosensitivity of small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Krarup, M; Poulsen, H S; Spang-Thomsen, M

    1997-01-01

    PURPOSE: The objective of this study was to determine the radiobiological characteristics of a panel of small-cell lung cancer (SCLC) cell lines by use of a clonogenic assay. In addition, we tested whether comparable results could be obtained by employing a growth extrapolation method based...

  6. Susceptibility testing of fish cell lines for virus isolation

    DEFF Research Database (Denmark)

    Ariel, Ellen; Skall, Helle Frank; Olesen, Niels Jørgen

    2009-01-01

    compare susceptibility between cell lines and between lineages within a laboratory and between laboratories (Inter-laboratory Proficiency Test). The objective being that the most sensitive cell line and lineages are routinely selected for diagnostic purposes.In comparing cell lines, we simulated "non......-cell-culture-adapted" virus by propagating the virus in heterologous cell lines to the one tested. A stock of test virus was produced and stored at - 80 °C and tests were conducted biannually. This procedure becomes complicated when several cell lines are in use and does not account for variation among lineages. In comparing...... cell lineages, we increased the number of isolates of each virus, propagated stocks in a given cell line and tested all lineages of that line in use in the laboratory. Testing of relative cell line susceptibility between laboratories is carried out annually via the Inter-laboratory Proficiency Test...

  7. Induced pluripotent stem cell lines derived from human somatic cells.

    Science.gov (United States)

    Yu, Junying; Vodyanik, Maxim A; Smuga-Otto, Kim; Antosiewicz-Bourget, Jessica; Frane, Jennifer L; Tian, Shulan; Nie, Jeff; Jonsdottir, Gudrun A; Ruotti, Victor; Stewart, Ron; Slukvin, Igor I; Thomson, James A

    2007-12-21

    Somatic cell nuclear transfer allows trans-acting factors present in the mammalian oocyte to reprogram somatic cell nuclei to an undifferentiated state. We show that four factors (OCT4, SOX2, NANOG, and LIN28) are sufficient to reprogram human somatic cells to pluripotent stem cells that exhibit the essential characteristics of embryonic stem (ES) cells. These induced pluripotent human stem cells have normal karyotypes, express telomerase activity, express cell surface markers and genes that characterize human ES cells, and maintain the developmental potential to differentiate into advanced derivatives of all three primary germ layers. Such induced pluripotent human cell lines should be useful in the production of new disease models and in drug development, as well as for applications in transplantation medicine, once technical limitations (for example, mutation through viral integration) are eliminated.

  8. Determination of IGF-1-Producing CHO-K1 Growth Phases Using GCMS-Based Global Metabolite Analysis

    Directory of Open Access Journals (Sweden)

    S. E. M. SABERI

    2011-12-01

    Full Text Available Mammalian cell lines, in particular CHO-K1 is vital for the multibillion dollar biotechnology industry. The majority of large scale bioprocessing of commercially valuable protein biopharmaceuticals is produced using this type of cell. An ideal mammalian cell system as host for biologics production should retain efficient use of energy sources in order to boost productivity at minimum cost. Various analyses such as cell counting and monitoring of specific biochemical responses are used to provide data to enable bioprocess control in order to achieve the ideal system. Our study aimed to see whether global metabolite analysis using Gas Chromatography Mass Spectrometry (GCMS would be a potential alternative approach in providing data for bioprocess control. In this study, we analyzed metabolites of CHO-K1 cells at different growth phases using GCMS. CHO-K1 cells producing insulin like growth factor-I (IGF1 were obtained from ATCC. Cells were grown in T-flask and incubated at 37°C/ 5% CO2 until 70-80% confluent in RPMI 1640 media. Samples (cells and spent/conditioned media were taken at designated intervals for routine cell counting (Trypan Blue dye exclusion method; glucose, glutamine and lactate determination (YSI 2700; IGF-1 production (ELISA kit R&D Sstems, Inc; and global metabolite analysis (GCMS. Conditioned media from each time point were spun down before subjecting into GCMS. Data from GCMS was then transferred to SIMCA P+12.0 for chemometric evaluation using Principal Component Analysis (PCA. The first component, PC1 results was able to explain 36% of the variation of the data with clear separation between exponential phase and other phases (initial and death phase. This suggests that GCMS-based global metabolite analysis has the ability to capture cell growth behaviour and offered insights of factors that may influence the biological system.ABSTRAK: Produk yang berupa sel kekal mamalia, terutamnya CHO-K1 adalah penting dan menguntungkan

  9. 77 FR 5489 - Identification of Human Cell Lines Project

    Science.gov (United States)

    2012-02-03

    ... Genetics Group Web site at http://www.nist.gov/mml/biochemical/genetics/index.cfm . Once the total number... methods for human cell line authentication the identity of a cell line need no longer be in doubt. NIST...

  10. Preparation of freeze-dried recombinant hepatitis B vaccine (CHO cells) reference%重组乙型肝炎疫苗(CHO细胞)冻干参考品的研制

    Institute of Scientific and Technical Information of China (English)

    邱少辉; 郭玉芬; 钟熙; 胡忠玉; 方鑫; 何鹏; 梁争论; 张红霞; 张卫婷; 赵坤福; 李德桂; 周根喜

    2012-01-01

    目的 制备重组乙型肝炎疫苗(CHO细胞)冻干参考品,用于重组乙型肝炎疫苗(CHO细胞)的效力评价.方法 选取检定合格的重组乙型肝炎疫苗(CHO细胞)原液,经协作标定表面抗原蛋白含量后,加入氢氧化铝佐剂和冻于保护剂,冷冻干燥制备重组乙型肝炎疫苗(CHO细胞)冻干参考品,并按《中国药典》三部(2010版)要求进行各项检定.经10次独立试验测定冻干参考品小鼠效力,采用Reed-Münch计算ED50值;将冻干参考品置4℃(8周)、37℃(4和8周)后分别检测疫苗效力,分析其稳定性,依据Q10法进行效期推测;并对2个生产企业10批疫苗进行效力测定,分析其适用性.结果 制备的冻干参考品各项指标均符合规定,小鼠ED50均值为0.183μg,CV为50.5%;该CHO细胞效力冻干参考品蛋白含量定为20 μg/ml,规格为10 μg/0.5 ml;冻干保护剂、冻干工艺对乙型肝炎疫苗(CHO细胞)的效力影响较小,冻干参考品在37℃放置不同时间,效力变化不明显,表明冻干参考品稳定性较好,有效期约为7年;10批疫苗中,不合格率为10%,表明该参考品可用于乙型肝炎疫苗(CHO细胞)效力质控.结论 制备的冻干参考品可作为重组乙型肝炎疫苗(CHO细胞)效力检定的质控参考品.%Objective To prepare freeze-dried recombinant hepatitis B vaccine(CHO cells) reference for evaluation of potency of recombinant hepatitis B vaccine (CHO cells). Methods Bulk of qualified recombinant hepatitis B vaccine (CHO cells) was se-lected as the raw material of reference. After collaborative calibration of HBsAg content, the bulk was added with aluminium adjuvant and preservative, then lyophilized to prepared freeze-dried recombinant hepatitis B vaccine reference on which overall control tests were performed according to the requirements in Chinese Pharmacopoeia (Volume Ⅲ, 2010 edition). The potency of the freeze-dried reference was determined by ten independent tests in mice, and

  11. Expression of Cyclooxygenase-2 in Ovarian Cancer Cell Lines

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To investigate the expression of cyclooxygenase-2 (COX-2) in ovarian cancer cell lines,RT-PCR and immunocytochemistry were used to detect the expression of COX-2 in 5 ovarian cancer cell lines. The expression of COX-2 mRNA and protein was detected in all 5 cell lines. It is suggested that COX-2 is expressed in ovarian cancer cell lines, which provides a basis for the chemoprevention of ovarian cancer.

  12. Radiosensitivity of Human Melanoma Cell Lines

    Energy Technology Data Exchange (ETDEWEB)

    Bergoc, R. M.; Medina, V.; Cricco, G.; Mohamed, N.; Martin, G.; Nunez, M.; Croci, M.; Crescenti, E. J.; Rivera, E. S.

    2004-07-01

    Cutaneous melanoma is a skin cancer resulting from the malign transformation of skin-pigment cells, the melanocytes. The radiotherapy, alone or in combination with other treatment, is an important therapy for this disease. the objective of this paper was to determine in vitro the radiosensitivity of two human melanoma cell lines with different metastatic capability: WM35 and MI/15, and to study the effect of drugs on radiobiological parameters. The Survival Curves were adjusted to the mathematical Linear-quadratic model using GrapsPad Prism software. Cells were seeded in RPMI medium (3000-3500 cells/flask), in triplicate and irradiated 24 h later. The irradiation was performed using an IBL 437C H Type equipment (189 TBq, 7.7 Gy/min) calibrated with a TLD 700 dosimeter. The range of Doses covered from 0 to 10 Gy and the colonies formed were counted at day 7th post-irradiation. Results obtained were: for WM35, {alpha}=0.37{+-}0.07 Gy''-1 and {beta}=0.06{+-}0.02 Gy''-2, for M1/15m {alpha}=0.47{+-}0.03 Gy''-1 and {beta}=0.06{+-}0.01 Gy''-2. The {alpha}/{beta} values WM35: {alpha}/{beta} values WM35: {alpha}/{beta}=6.07 Gy and M1/15: {alpha}/{beta}{sub 7}.33 Gy were similar, independently of their metastatic capabillity and indicate that both lines exhibit high radioresistance. Microscopic observation of irradiated cells showed multinuclear cells with few morphologic changes non-compatible with apoptosis. By means of specific fluorescent dyes and flow cytometry analysis we determined the intracellular levels of the radicals superoxide and hydrogen peroxide and their modulation in response to ionizing radiation. The results showed a marked decreased in H{sub 2}O{sub 2} intracellular levels with a simultaneous increase in superoxide that will be part of a mechanism responsible for induction of cell radioresistance. This response triggered by irradiated cells could not be abrogated by different treatments like histamine or the

  13. The impact of pH inhomogeneities on CHO cell physiology and fed-batch process performance - two-compartment scale-down modelling and intracellular pH excursion.

    Science.gov (United States)

    Brunner, Matthias; Braun, Philipp; Doppler, Philipp; Posch, Christoph; Behrens, Dirk; Herwig, Christoph; Fricke, Jens

    2017-01-12

    Due to high mixing times and base addition from top of the vessel, pH inhomogeneities are most likely to occur during large-scale mammalian processes. The goal of this study was to set-up a scale-down model of a 10-12 m(3) stirred tank bioreactor and to investigate the effect of pH perturbations on CHO cell physiology and process performance. Short-term changes in extracellular pH are hypothesized to affect intracellular pH and thus cell physiology. Therefore, batch fermentations, including pH shifts to 9.0 and 7.8, in regular one-compartment systems are conducted. The short-term adaption of the cells intracellular pH are showed an immediate increase due to elevated extracellular pH. With this basis of fundamental knowledge, a two-compartment system is established which is capable of simulating defined pH inhomogeneities. In contrast to state-of-the-art literature, the scale-down model is included parameters (e.g. volume of the inhomogeneous zone) as they might occur during large-scale processes. pH inhomogeneity studies in the two-compartment system are performed with simulation of temporary pH zones of pH 9.0. The specific growth rate especially during the exponential growth phase is strongly affected resulting in a decreased maximum viable cell density and final product titer. The gathered results indicate that even short-term exposure of cells to elevated pH values during large-scale processes can affect cell physiology and overall process performance. In particular, it could be shown for the first time that pH perturbations, which might occur during the early process phase, have to be considered in scale-down models of mammalian processes.

  14. EXPRESSION OF Fas LIGAND IN HUMAN COLON CANCER CELL LINES

    Institute of Scientific and Technical Information of China (English)

    张建军; 丁尔迅; 王强; 陈学云; 付志仁

    2001-01-01

    To investigate the expression of Fas ligand in human colon carcinoma cell lines. Methods: A total of six human colon cancer cell lines were examined for the expression of Fas ligand mRNA and cell surface protein by using RT-PCR and flow cytometry respectively. Results: The results showed that Fas ligand mRNA was expressed in all of the six cancer cell lines and Fas ligand cell surface protein was expressed in part of them. Conclusion: These data suggest that Fas ligand was expressed, at least in part, in human colon cancer cell lines and might facilitate to escape from immune surveillance of the host.

  15. Biological characteristics of cell lines of human dental alveolus

    Institute of Scientific and Technical Information of China (English)

    陈世璋; 黄靖香; 孙明学; 赵斌

    2003-01-01

    Objective To investigate the biological characteristics of cell lines of healthy and diseased human dental alveoli. Methods Primary cell lines from either healthy or diseased human dental alveoli were obtained. Two cell lines, H-258 and H-171 derived from healthy and diseased human tissues respectively, were selected for morphological study and research on their growth and aging, using cell counting, and histochemical and immunohistochemical staining. Results Primary cell lines were successfully established from innormal dental alveoli. After freezing and thawing for three times, cell growth was continued and no morphological alterations were observed. The doubling time was 53.4 hours and mean division index (MDI) was 4‰. Cells were kept normal after twenty generations with no obvious reduction of doubling time and MDI. Of twenty-six primary cell lines derived from healthy human dental alveoli, only three cell lines achieved generation. After freezing and thawing for twice, cultured cells were still alive at a decreased growth speed, with doubling time of 85.9 hours and MDI of 3‰. Both cell lines, H-171 and H-258, shared the characteristics of osteoblast. Conclusions Primary cell lines of diseased human dental alveoli show greater growth potential. All cell lines of dental alveoli share characteristics of osteoblast. The technique we developed may be put into practice for the treatment of abnormal dental alveoli.

  16. Molluscan cells in culture: primary cell cultures and cell lines

    OpenAIRE

    2013-01-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as bi...

  17. In vitro radiosensitivity of human leukemia cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Weichselbaum, R.R.; Greenberger, J.S.; Schmidt, A.; Karpas, A.; Moloney, W.C.; Little, J.B.

    1981-05-01

    The in vitro radiobiologic survival values (anti n, D/sub 0/) of four tumor lines derived from human hematopoietic tumors were studied. These cell lines were HL60 promyelocytic leukemia; K562 erythroleukemia; 45 acute lymphocytic leukemia; and 176 acute monomyelogenous leukemia. More cell lines must be examined before the exact relationship between in vitro radiosensitivity and clinical radiocurability is firmly established.

  18. Characterization of a Chinese hamster-human hybrid cell line with increased system L amino acid transport activity.

    Science.gov (United States)

    Lobaton, C D; Moreno, A; Oxender, D L

    1984-03-01

    We have studied leucine transport in several Chinese hamster-human hybrid cell lines obtained by fusion of a temperature-sensitive line of Chinese hamster ovary cells, ts025C1, and normal human leukocytes. A hybrid cell line exhibiting a twofold increase in L-leucine uptake over that in the parental cell line was found. This hybrid cell line, 158CnpT-1, was temperature resistant, whereas the parental Chinese hamster ovary mutant, ts025C1, contained a temperature-sensitive leucyl-tRNA synthetase mutation. An examination of the different amino acid transport systems in this hybrid cell line revealed a specific increase of system L activity with no significant changes in systems A and ASC. The Vmax for L-leucine uptake exhibited by the hybrid 158CnpT-1 was twice that in the CHO parental mutant, ts025C1. Cytogenetic analysis showed that the hybrid 158CnpT-1 contains four complete human chromosomes (numbers 4, 5, 10, and 21) and three interspecific chromosomal translocations in a total complement of 34 chromosomes. Biochemical and cytogenetic analysis of segregant clones obtained from hybrid 158CnpT-1 showed that the primary temperature resistance and high system L transport phenotypes can be segregated from this hybrid independently. The loss of the primary temperature resistance was associated with the loss of the human chromosome 5, as previously reported by other laboratories, whereas the loss of the high leucine transport phenotype, which is associated with a lesser degree of temperature resistance, was correlated with the loss of human chromosome 20.

  19. Effects of sulfated fucan, ascophyllan, from the brown Alga Ascophyllum nodosum on various cell lines: a comparative study on ascophyllan and fucoidan.

    Science.gov (United States)

    Jiang, Zedong; Okimura, Takasi; Yokose, Takeshi; Yamasaki, Yasuhiro; Yamaguchi, Kenichi; Oda, Tatsuya

    2010-07-01

    The effects of fucose-containing sulfated polysaccharides, ascophyllan and fucoidan, isolated from the brown alga Ascophyllum nodosum, on the growth of various cell lines (MDCK, Vero, PtK(1), CHO, HeLa, and XC) were investigated. In a colony formation assay, ascophyllan and fucoidan showed potent cytotoxic effects on Vero and XC cells, while other cell lines were relatively resistant to these polysaccharides. Almost no significant effects of these polysaccharides were observed in the cell lines tested using the Alamar blue cytotoxicity assay over 48 h with varying initial cell densities (2500-20,000 cells/well) in growth medium. Interestingly, a significant growth promoting effect of ascophyllan on MDCK cells was observed, whereas treatment with fucoidan showed growth suppressive effects on this cell line under the same experimental conditions. These results suggest that ascophyllan is distinguishable from fucoidan in terms of their bioactivities. This is the first report of the growth promoting effects of a sulfated fucan on a mammalian cell line under normal growth conditions.

  20. 抗肿瘤坏死因子相关凋亡诱导配体受体2嵌合抗体表达载体的构建、表达及其抗肿瘤活性分析%Construction and stable expression of anti-human tumor necrosis factor-related apoptosis-inducing ligand receptor 2 chimeric antibody in CHO cells

    Institute of Scientific and Technical Information of China (English)

    吕付佳; 史娟; 张亚玺; 刘士廉; 刘彦信; 郑德先

    2011-01-01

    目的:构建抗人肿瘤坏死因子相关凋亡诱导配体(TRAIL)受体2(死亡受体5,DR5)的人-鼠嵌合抗体表达载体,获得稳定表达该嵌合抗体的细胞株,并分析嵌合抗体的抗肿瘤活性.方法:采用DNA重组技术,扩增抗人DR5的鼠源单克隆抗体(mAb)AD5-10的重链(HC)、轻链(LC)可变区基因片段,并将其分别插入含有人IgG重链、轻链恒定区基因的真核表达载体RpCI-neo,以重、轻链表达质粒共转染中国仓鼠卵巢细胞(CHO),筛选稳定表达抗人DR5嵌合抗体(hmAD5-10)的重组细胞.采用Western blot和间接ELISA检测嵌合抗体的表达量及其与抗原DR5的结合活性.采用MTS比色法检测嵌合抗体的生物学活性.并对重组细胞株进行无血清培养驯化.结果:获得了2株稳定表达嵌合抗体的重组细胞株CHO-A5和CHO-B11,抗体的表达水平分别为(0.36±0.11)mg/L和(0.16±0.01)mg/L,嵌合抗体与DR5有较好的结合活性,对体外培养的人T淋巴细胞白血病细胞SVT35有显著的杀伤作用.结论:在真核细胞中表达了具有生物学活性的抗DR5的人-鼠嵌合抗体,为其应用于肿瘤治疗研究奠定了基础.%AIM: To establish an human-mouse chimeric antibody against tumor necrosis factor-related apoptosisinducing ligand (TRAIL) receptor 2 (death receptor 5, DR5) in an eukaryotic cell line and analyse ifs tumoricidal activity. METHODS: The cDNAs encoding for the variable regions of heavy chain (VH) and light chain (VL) of AD5-10 were amplified by PCR and inserted into the human lgG heavy and light chain containing expression vector RpClneo, respectively. The recombinant plasmids were co-transfected into HEK293 and/or CHO cells. The production of anti-DR5 human-mouse chimeric antibody (hmAD5-10) and the antibody affinity for DR5 were identified by ELISA and Western blot assay. The tumoricidal activity of hmAD5-10 was demonstrated by MTS assay. The stable expression cells were selected and cultured in serum-free medium

  1. Cloning of aminopeptidase Npromoter and its activity in hematopoietic cell and different tumor cell lines

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Aminopeptidase N (APN) promoter region was cloned and sequenced from peripheral blood mononuclear cells. The recombinant reporter construct containing the promoter and luciferase gene, designated pXP1-APNLuc, was introduced into myeloblastic cell line, T lymphocyte cell line and various tumor cell lines. Luciferase assay showed that APN upstream promoter is myeloid-specific for high expression in myeloblastic cell line and much lower expres sion in T lymphocyte cell line. The promoter activity was relatively high in lung adenoma cell line compared with other tumor cell lines including hepatoma cell line, tong cancer cell line and esophageal cancer cell line in which the promoter activity significantly diminished or was almost undetectable. The characteristics of APN promoter may pro vide a new strategy for specific myeloprotection while tumor patients are being treated with chemotherapy and/or radio therapy.

  2. MODERATE CYTOTOXICITY OF PROANTHOCYANIDINS TO HUMAN TUMOR-CELL LINES

    NARCIS (Netherlands)

    KOLODZIEJ, H; HABERLAND, C; WOERDENBAG, HJ; KONINGS, AWT

    1995-01-01

    In the present study the cytotoxicity of 16 proanthocyanidins was evaluated in GLC(4), a human small cell lung carcinoma cell line, and in COLO 320, a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. With IC50 values ranging from 18 to >200 mu m following continuous

  3. Comparative analysis of the internalization of the macrophage receptor sialoadhesin in human and mouse primary macrophages and cell lines.

    Science.gov (United States)

    De Schryver, Marjorie; Leemans, Annelies; Pintelon, Isabel; Cappoen, Davie; Maes, Louis; Caljon, Guy; Cos, Paul; Delputte, Peter L

    2016-11-21

    Sialoadhesin (Sn) is a surface receptor expressed on resident macrophages with the ability to bind with sialic acids. During inflammation, an upregulation of Sn is observed. Upon binding of monoclonal antibodies to Sn, the receptor becomes internalized and this has been observed in multiple species. The latter characteristic, combined with the strong upregulation of Sn on inflammatory macrophages and the fact that Sn-positive macrophages contribute to certain inflammatory diseases, makes Sn an interesting entry portal for phenotype-modulating or cytotoxic drugs. Such drugs or toxins can be linked to Sn-specific antibodies which should enable their targeted uptake by macrophages. However, the activity of such drugs depends not only on their internalization but also on the intracellular trafficking and final fate in the endolysosomal system. Although information is available for porcine Sn, the detailed mechanisms of human and mouse Sn internalization and subsequent intracellular trafficking are currently unknown. To allow development of Sn-targeted therapies, differences across species and cellular background need to be characterized in more detail. In the current report, we show that internalization of human and mouse Sn is dynamin-dependent and clathrin-mediated, both in primary macrophages and CHO cell lines expressing a recombinant Sn. In primary macrophages, internalized Sn-specific F(ab')2 fragments are located mostly in the early endosomes. With Fc containing Sn-specific antibodies, there is a slight shift towards lysosomal localization in mouse macrophages, possibly because of an interaction with Fc receptors. Surprisingly, in CHO cell lines expressing Sn, there is a predominant lysosomal localization. Our results show that the mechanism of Sn internalization and intracellular trafficking is concurrent in the tested species. The cellular background in which Sn is expressed and the type of antibody used can affect the intracellular fate, which in turn can

  4. Evidence that phosphatidylcholine-specific phospholipase C is a key molecule mediating insulin-induced enhancement of gene expression from human cytomegalovirus promoter in CHO cells

    OpenAIRE

    Zhang, Yingpei; Katakura, Yoshinori; Seto, Perry; Shirahata, Sanetaka

    1997-01-01

    The signal transduction from insulin to its receptors and Ras has been extensively studied, while little has been reported beyond these steps. We found that the expression of human interleukin 6 gene under the control of immediate early gene promoter of human cytomegalovirus was enhanced by insulin sitmulation in Chinese hamster ovary cells. The induction effect of insulin was not significantly affected by inhibitors or activators of conventional protein kinase C, cAMP dependent protein kinas...

  5. POTENTIAL CELL LINE TOXICITY OF ENVIRONMENTAL NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Mohan Durga

    2012-01-01

    Full Text Available In India, the unprecedented growth rate and urbanization along with the rapid increase in motor vehicle activity and industrialization are contributing to high levels of urban air pollution. The population is mainly exposed to high air pollution concentrations, where motor vehicle emissions constitute the main source of fine and ultrafine particles. Motor exhaust emissions is a mixture of gases and Particulate Matter (PM. Diesel and petrol fuels in vehicles produce combustion-derived particles as a result of combustion. Vehicle exhaust particles are the main constituents of environmental nanoparticles. In the present investigation, environmental nanoparticles such as Diesel Exhaust Particles (DEP and Petrol Exhaust Particles (PEP were collected from on-road vehicles using a specially designed collection chamber. The surface morphology of the collected particles was analyzed through Transmission Electron Microscope (TEM, and the elemental mapping was performed through EDAX analysis. Results indicated the presence of nanometer-size particles in both the categories of vehicle exhaust. These small-size particles of respirable range can enter the respiratory tract of humans and get deposited in the lungs and cause various effects inside the human body. The aim of this study is to assess the cytotoxicity of the collected Diesel Exhaust Nanoparticles (DENPs and Petrol Exhaust Nanoparticles (PENPs. Cytotoxicity endpoint, such as IC50 (50% Inhibitory Concentration, was determined after a 24-h exposure. Results of this study indicated that all five cell lines were sensitive to these vehicle exhaust nanoparticles at varying levels.

  6. Derivation and Utilization of Functional CD8(+) Dendritic Cell Lines.

    Science.gov (United States)

    Pigni, Matteo; Ashok, Devika; Acha-Orbea, Hans

    2016-01-01

    It is notoriously difficult to obtain large quantities of non-activated dendritic cells ex vivo. For this reason, we produced and characterized a mouse model expressing the large T oncogene under the CD11c promoter (Mushi mice), in which CD8α(+) dendritic cells transform after 4 months. We derived a variety of stable cell lines from these primary lines. These cell lines reproducibly share with freshly isolated dendritic cells most surface markers, mRNA and protein expression, and all tested biological functions. Cell lines can be derived from various strains and knockout mice and can be easily transduced with lentiviruses. In this article, we describe the derivation, culture, and lentiviral transduction of these dendritic cell lines.

  7. The human CFTR protein expressed in CHO cells activates aquaporin-3 in a cAMP-dependent pathway: study by digital holographic microscopy.

    Science.gov (United States)

    Jourdain, Pascal; Becq, Frédéric; Lengacher, Sylvain; Boinot, Clément; Magistretti, Pierre J; Marquet, Pierre

    2014-02-01

    The transmembrane water movements during cellular processes and their relationship to ionic channel activity remain largely unknown. As an example, in epithelial cells it was proposed that the movement of water could be directly linked to cystic fibrosis transmembrane conductance regulator (CFTR) protein activity through a cAMP-stimulated aqueous pore, or be dependent on aquaporin. Here, we used digital holographic microscopy (DHM) an interferometric technique to quantify in situ the transmembrane water fluxes during the activity of the epithelial chloride channel, CFTR, measured by patch-clamp and iodide efflux techniques. We showed that the water transport measured by DHM is fully inhibited by the selective CFTR blocker CFTRinh172 and is absent in cells lacking CFTR. Of note, in cells expressing the mutated version of CFTR (F508del-CFTR), which mimics the most common genetic alteration encountered in cystic fibrosis, we also show that the water movement is profoundly altered but restored by pharmacological manipulation of F508del-CFTR-defective trafficking. Importantly, whereas activation of this endogenous water channel required a cAMP-dependent stimulation of CFTR, activation of CFTR or F508del-CFTR by two cAMP-independent CFTR activators, genistein and MPB91, failed to trigger water movements. Finally, using a specific small-interfering RNA against the endogenous aquaporin AQP3, the water transport accompanying CFTR activity decreased. We conclude that water fluxes accompanying CFTR activity are linked to AQP3 but not to a cAMP-stimulated aqueous pore in the CFTR protein.

  8. The human CFTR protein expressed in CHO cells activates aquaporin-3 in a cAMP-dependent pathway: study by digital holographic microscopy

    KAUST Repository

    Jourdain, P.

    2013-12-11

    The transmembrane water movements during cellular processes and their relationship to ionic channel activity remain largely unknown. As an example, in epithelial cells it was proposed that the movement of water could be directly linked to cystic fibrosis transmembrane conductance regulator (CFTR) protein activity through a cAMP-stimulated aqueous pore, or be dependent on aquaporin. Here, we used digital holographic microscopy (DHM) an interferometric technique to quantify in situ the transmembrane water fluxes during the activity of the epithelial chloride channel, CFTR, measured by patch-clamp and iodide efflux techniques. We showed that the water transport measured by DHM is fully inhibited by the selective CFTR blocker CFTRinh172 and is absent in cells lacking CFTR. Of note, in cells expressing the mutated version of CFTR (F508del-CFTR), which mimics the most common genetic alteration encountered in cystic fibrosis, we also show that the water movement is profoundly altered but restored by pharmacological manipulation of F508del-CFTR-defective trafficking. Importantly, whereas activation of this endogenous water channel required a cAMP-dependent stimulation of CFTR, activation of CFTR or F508del-CFTR by two cAMP-independent CFTR activators, genistein and MPB91, failed to trigger water movements. Finally, using a specific small-interfering RNA against the endogenous aquaporin AQP3, the water transport accompanying CFTR activity decreased. We conclude that water fluxes accompanying CFTR activity are linked to AQP3 but not to a cAMP-stimulated aqueous pore in the CFTR protein.

  9. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...... except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein......The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...

  10. A new reliable bioassay for determining the biological activity of human interleukin-12 by using human NK cell line NKG cells.

    Science.gov (United States)

    Cheng, Min; Fei, Baozhen; Zheng, Xiaodong; Chen, Yongyan; Sun, Rui; Wei, Haiming; Tian, Zhigang

    2012-05-01

    A specific and accurate bioassay for determining the biological activity of human interleukin-12 (hIL-12), an important typical Th1 cytokine in both innate and adaptive immunity, is extensively required for biomedical and clinical study. In this paper, we used a new established NK cell line NKG cells as the responder to hIL-12 stimulation by detecting their IFN-γ production. It was found that NKG cells produced high level of IFN-γ when simulated by hIL-12, and the dose-response curve became the best Sigmoid curve (R(2)=0.9977, pbioassay was precise and reproducible. Furthermore, no obvious cross-effects of other cytokines such as IL-2 and IL-18 was observed on the bioassay. Addition of the neutralizing anti-hIL-12 antibody to the bioassay significantly inhibited the IFN-γ production in a dose dependent manner, indicating that the bioactivity was actually mediated by hIL-12. The bioassay by using NKG cells was also suitable for determining the biological activity of recombinant hIL-12 in the form of purified product or culture supernatant by CHO-hIL-12 cell line. In conclusion, a reliable hIL-12 bioassay for determining its biological activity was established by using NKG cells as a responder and measuring their production of IFN-γ.

  11. Authentication of the R06E Fruit Bat Cell Line

    Directory of Open Access Journals (Sweden)

    Ingo Jordan

    2012-05-01

    Full Text Available Fruit bats and insectivorous bats are believed to provide a natural reservoir for a wide variety of infectious diseases. Several lines of evidence, including the successful isolation of infectious viruses, indicate that Marburg virus and Ravn virus have found a major reservoir in colonies of the Egyptian rousette (Rousettus aegyptiacus. To facilitate molecular studies on virus-reservoir host interactions and isolation of viruses from environmental samples, we established cell lines from primary cells of this animal. The cell lines were given to several laboratories until we realized that a contamination with Vero cells in one of the cultures had occurred. Here we describe a general diagnostic procedure for identification of cross-species contamination with the focus on Vero and Rousettus cell lines, and summarize newly discovered properties of the cell lines that may pertain to pathogen discovery.

  12. Understanding the mechanism of virus removal by Q sepharose fast flow chromatography during the purification of CHO-cell derived biotherapeutics.

    Science.gov (United States)

    Strauss, Daniel M; Lute, Scott; Tebaykina, Zinaida; Frey, Douglas D; Ho, Cintia; Blank, Gregory S; Brorson, Kurt; Chen, Qi; Yang, Bin

    2009-10-01

    During production of therapeutic monoclonal antibodies (mAbs) in mammalian cell culture, it is important to ensure that viral impurities and potential viral contaminants will be removed during downstream purification. Anion exchange chromatography provides a high degree of virus removal from mAb feedstocks, but the mechanism by which this is achieved has not been characterized. In this work, we have investigated the binding of three viruses to Q sepharose fast flow (QSFF) resin to determine the degree to which electrostatic interactions are responsible for viral clearance by this process. We first used a chromatofocusing technique to determine the isoelectric points of the viruses and established that they are negatively charged under standard QSFF conditions. We then determined that virus removal by this chromatography resin is strongly disrupted by the presence of high salt concentrations or by the absence of the positively charged Q ligand, indicating that binding of the virus to the resin is primarily due to electrostatic forces, and that any non-electrostatic interactions which may be present are not sufficient to provide virus removal. Finally, we determined the binding profile of a virus in a QSFF column after a viral clearance process. These data indicate that virus particles generally behave similarly to proteins, but they also illustrate the high degree of performance necessary to achieve several logs of virus reduction. Overall, this mechanistic understanding of an important viral clearance process provides the foundation for the development of science-based process validation strategies to ensure viral safety of biotechnology products.

  13. Effect of leptin on cell proliferation and apoptosis of gastric adenocarcinoma cell line-SGC7901 and colon cancer cell line-HT-29

    Institute of Scientific and Technical Information of China (English)

    Chang-Wen Yu; Bi-Sheng Zhu

    2016-01-01

    Objective:To explore effect of leptin on cell proliferation and apoptosis of gastric adenocarcinoma cell line-SGC7901 and colon cancer cell line-HT-29.Methods: MTT and flow cytometry were adopted for detecting the effect of exogenous leptin on cell cycle of gastric adenocarcinoma cell line-SGC7901 and colon cancer cell line-HT-29.Results: Leptin with mass concentration (0 ng/mL, 5 ng/mL, 50 ng/mL, 100 ng/mL, 200 ng/mL) could stimulate the growth of gastric adenocarcinoma cell line-SGC7901 and colon cancer cell line-HT-29; exogenous leptin with mass concentration (5 ng/mL, 50 ng/mL, 100 ng/mL, 200 ng/mL) could inhibit cell growth of gastric adenocarcinoma cell line-SGC7901 and colon cancer cell line-HT-29 after 72 h; among which, inhibiting effects of cell line-SGC7901 and cell line-HT-29 were the most significant under the effect of exogenous leptin with mass concentration-200 ng/mL.Conclusion:Within a certain concentration and action time, exogenous leptin can stimulate the growth of gastric adenocarcinoma cell line and colon cancer cell line, and then promot the tumor cell proliferation and/or inhibit the tumor cell apoptosis.

  14. Cancer and inflammation studies using zebrafish cell lines

    NARCIS (Netherlands)

    He, Shuning

    2010-01-01

    As the zebrafish, Danio rerio, has been increasingly used as an animal model for biomedical research, we aimed to establish zebrafish cell line models for inflammation and cancer studies in this thesis. Several zebrafish cell lines were characterized and their genetic and physiological properties we

  15. Derivation of the human embryonic stem cell line RCM1

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCM-1 was derived from a failed to fertilise egg undergoing parthenogenetic stimulation. The cell line shows normal pluripotency marker expression and differentiation to three germ layers in vitro and in vivo. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  16. Trichloroethylene toxicity in a human hepatoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Thevenin, E.; McMillian, J. [Medical Univ. of Charleston South Carolina, SC (United States)

    1994-12-31

    The experiments conducted in this study were designed to determine the usefullness of hepatocyte cultures and a human hepatoma cell line as model systems for assessing human susceptibility to hepatocellular carcinoma due to exposure to trichloroethylene. The results from these studies will then be analyzed to determine if human cell lines can be used to conduct future experiments of this nature.

  17. Beryllium-stimulated apoptosis in macrophage cell lines.

    Science.gov (United States)

    Sawyer, R T; Fadok, V A; Kittle, L A; Maier, L A; Newman, L S

    2000-08-21

    In vitro stimulation of bronchoalveolar lavage cells from patients with chronic beryllium disease (CBD) induces the production of TNF-alpha. We tested the hypothesis that beryllium (Be)-stimulated TNF-alpha might induce apoptosis in mouse and human macrophage cell lines. These cell lines were selected because they produce a range of Be-stimulated TNF-alpha. The mouse macrophage cell line H36.12j produces high levels of Be-stimulated TNF-alpha. The mouse macrophage cell line P388D.1 produces low, constitutive, levels of TNF-alpha and does not up-regulate Be-stimulated TNF-alpha production. The DEOHS-1 human CBD macrophage cell line does not produce constitutive or Be-stimulated TNF-alpha. Apoptosis was determined by microscopic observation of propidium iodide stained fragmented nuclei in unstimulated and BeSO(4)-stimulated macrophage cell lines. BeSO(4) induced apoptosis in all macrophage cell lines tested. Beryllium-stimulated apoptosis was dose-responsive and maximal after 24 h of exposure to 100 microM BeSO(4). In contrast, unstimulated and Al(2)(SO(4))(3)-stimulated macrophage cell lines did not undergo apoptosis. The general caspase inhibitor BD-fmk inhibited Be-stimulated macrophage cell line apoptosis at concentrations above 50 microM. Our data show that Be-stimulated macrophage cell line apoptosis was caspase-dependent and not solely dependent on Be-stimulated TNF-alpha levels. We speculate that the release of Be-antigen from apoptotic macrophages may serve to re-introduce Be material back into the lung microenvironment, make it available for uptake by new macrophages, and thereby amplify Be-stimulated cytokine production, promoting ongoing inflammation and granuloma maintenance in CBD.

  18. Regulated expression of erythropoietin by two human hepatoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, M.A.; Glass, G.A.; Cunningham, J.M.; Bunn, H.F.

    1987-11-01

    The development of a cell culture system that produces erythropoietin (Epo) in a regulated manner has been the focus of much effort. The authors have screened multiple renal and hepatic cell lines for either constitutive or regulated expression of Epo. Only the human hepatoma cell lines, Hep3B and HepG2, made significant amounts of Epo as measured both by radioimmunoassay and in vitro bioassay (as much as 330 milliunits per 10/sup 6/ cells in 24 hr). The constitutive production of Epo increased dramatically as a function of cell density in both cell lines. At cell densities < 3.3 x 10/sup 5/ cells per cm/sup 2/, there was little constitutive release of Epo in the medium. With Hep3B cells grown at low cell densities, a mean 18-fold increase in Epo expression was seen in response to hypoxia and a 6-fold increase was observed in response to incubation in medium containing 50 ..mu..M cobalt(II) chloride. At similar low cell densities, Epo production in HepG2 cells could be enhanced an average of about 3-fold by stimulation with either hypoxia or cobalt(II) chloride. Upon such stimulation, both cell lines demonstrated markedly elevated levels of Epo mRNA. Hence, both Hep3B and HepG2 cell lines provide an excellent in vitro system in which to study the physiological regulation of Epo expression.

  19. Human embryonic stem cell lines derived from the Chinese population

    Institute of Scientific and Technical Information of China (English)

    Zhen Fu FANG; Fan JIN; Hui GAI; Ying CHEN; Li WU; Ai Lian LIU; Bin CHEN; Hui Zhen SHENG

    2005-01-01

    Six human embryonic stem cell lines were established from surplus blastocysts. The cell lines expressed alkaline phosphatase and molecules typical of primate embryonic stem cells, including Oct-4, Nanog, TDGF1, Sox2, EBAF,Thy-1, FGF4, Rex-1, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. Five of the six lines formed embryoid bodies that expressed markers of a variety of cell types; four of them formed teratomas with tissue types representative of all three embryonic germ layers. These human embryonic stem cells are capable of producing clones of undifferentiated morphology, and one of them was propagated to become a subline. Human embryonic stem cell lines from the Chinese population should facilitate stem cell research and may be valuable in studies of population genetics and ecology.

  20. Motoneuron differentiation of immortalized human spinal cord cell lines.

    Science.gov (United States)

    Li, R; Thode, S; Zhou, J; Richard, N; Pardinas, J; Rao, M S; Sah, D W

    2000-02-01

    Human motoneuron cell lines will be valuable tools for spinal cord research and drug discovery. To create such cell lines, we immortalized NCAM(+)/neurofilament(+) precursors from human embryonic spinal cord with a tetracycline repressible v-myc oncogene. Clonal NCAM(+)/neurofilament(+) cell lines differentiated exclusively into neurons within 1 week. These neurons displayed extensive processes, exhibited immunoreactivity for mature neuron-specific markers such as tau and synaptophysin, and fired action potentials upon current injection. Moreover, a clonal precursor cell line gave rise to multiple types of spinal cord neurons, including ChAT(+)/Lhx3(+)/Lhx4(+) motoneurons and GABA(+) interneurons. These neuronal restricted precursor cell lines will expedite the elucidation of molecular mechanisms that regulate the differentiation, maturation and survival of specific subsets of spinal cord neurons, and the identification and validation of novel drug targets for motoneuron diseases and spinal cord injury.

  1. Derivation of human embryonic stem cell line Genea022

    Directory of Open Access Journals (Sweden)

    Biljana Dumevska

    2016-03-01

    Full Text Available The Genea022 human embryonic stem cell line was derived from a donated, fully commercially consented ART blastocyst, through ICM outgrowth on inactivated feeders. The line showed pluripotent cell morphology and genomic analysis verified a 46, XY karyotype and male allele pattern through CGH and STR analysis. Pluripotency of Genea022 was demonstrated with 84% of cells expressed Nanog, 98% Oct4, 55% Tra1–60 and 97% SSEA4, gave a Pluritest Pluripotency score of 42.95, Novelty of 1.23, demonstrated Alkaline Phosphatase activity and tri-lineage teratoma formation. The cell line was negative for Mycoplasma and visible contamination.

  2. Further characterization of the first seminoma cell line TCam-2.

    Science.gov (United States)

    de Jong, Jeroen; Stoop, Hans; Gillis, Ad J M; Hersmus, Remko; van Gurp, Ruud J H L M; van de Geijn, Gert-Jan M; van Drunen, Ellen; Beverloo, H Berna; Schneider, Dominik T; Sherlock, Jon K; Baeten, John; Kitazawa, Sohei; van Zoelen, E Joop; van Roozendaal, Kees; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2008-03-01

    Testicular germ cell tumors of adolescents and adults (TGCTs) can be classified into seminomatous and nonseminomatous tumors. Various nonseminomatous cell lines, predominantly embryonal carcinoma, have been established and proven to be valuable for pathobiological and clinical studies. So far, no cell lines have been derived from seminoma which constitutes more than 50% of invasive TGCTs. Such a cell line is essential for experimental investigation of biological characteristics of the cell of origin of TGCTs, i.e., carcinoma in situ of the testis, which shows characteristics of a seminoma cell. Before a cell line can be used as model, it must be verified regarding its origin and characteristics. Therefore, a multidisciplinary approach was undertaken on TCam-2 cells, supposedly the first seminoma cell line. Fluorescence in situ hybridization, array comparative genomic hybridization, and spectral karyotyping demonstrated an aneuploid DNA content, with gain of 12p, characteristic for TGCTs. Genome wide mRNA and microRNA expression profiling supported the seminoma origin, in line with the biallelic expression of imprinted genes IGF2/H19 and associated demethylation of the imprinting control region. Moreover, the presence of specific markers, demonstrated by immunohistochemistry, including (wild type) KIT, stem cell factor, placental alkaline phosphatase, OCT3/4 (also demonstrated by a specific Q-PCR) and NANOG, and the absence of CD30, SSX2-4, and SOX2, confirms that TCam-2 is a seminoma cell line. Although mutations in oncogenes and tumor suppressor genes are rather rare in TGCTs, TCam-2 had a mutated BRAF gene (V600E), which likely explains the fact that these cells could be propagated in vitro. In conclusion, TCam-2 is the first well-characterized seminoma-derived cell line, with an exceptional mutation, rarely found in TGCTs.

  3. Establishment of Germ-line Competent C57BL/6J Embryonic Stem Cell Lines

    Institute of Scientific and Technical Information of China (English)

    Gui-jun YAN; Zheng GU; Jian WANG; Jia-ke TSO

    2004-01-01

    Objective To establish C57BL/6J embryonic stem (ES) cell lines with potential germline contribution Methods ES cells were isolated from blastocyst inner cell mass of C57BL/6J mice, and cultured for 15 passages, and then injected into blastococels of lCR mice blastocysts to establish chimeric mice.Results Three ES cell lines (mC57ESl,mC57ES3, mC57ES7) derived from the inner cell mass of C57BL/6J mice blastocysts were established. They were characteristic of undifferentiated state, including normal XY karyotype, expression of a specific cell surface marker "stage-specific embryonic antigen-1" and alkaline phosphatase in continuous passage. When injected into immunodeficient mice, mC5 7ES1 cells consis tently differentiated into derivatives of all three embryonic germ layers. When mC57ES1cells were transferred into ICR mice blastocysts, 4 chimeric mice have been obtained.One male of them revealed successful germ-line transmission. Conclussion We have obtained C57BL/6J ES cell lines with a potential germ-line contribution, which can be used to generate transgenic and gene knock-out mice.

  4. Cytotoxinic Mechanism of Hydroxyapatite Nanoparticles on Human Hepatoma Cell Lines

    Institute of Scientific and Technical Information of China (English)

    CAO Xian-ying; QI Zhi-tao; DAI Hong-lian; YAN Yu-hua; LI Shi-pu

    2003-01-01

    Stable and single-dispersed HAP nanoparticles were synthesized with chemical method assisted by ultrasonic treatment.HAP nanoparticles were surveyed by AFM and Zataplus.The effect on the Bel-7402 human hepatoma cell lines treated with HAP nanoparticles was investigated by the MTT methods and observation of morphology,and the mechanism was studied in changes of cell cycle and ultrastructure.The result shows that inhibition of HAP nanoparticles on the Bel-7402 human hepatoma cell lines is obviously in vitro.HAP nanoparticles the entered cancer cytoplasm,and cell proliferation is stopped at G1 phase of cell cycle,thus,cancer cells die directly.

  5. Deriving cell lines from zebrafish embryos and tumors.

    Science.gov (United States)

    Choorapoikayil, Suma; Overvoorde, John; den Hertog, Jeroen

    2013-09-01

    Over the last two decades the zebrafish has emerged as a powerful model organism in science. The experimental accessibility, the broad range of zebrafish mutants, and the highly conserved genetic and biochemical pathways between zebrafish and mammals lifted zebrafish to become one of the most attractive vertebrate models to study gene function and to model human diseases. Zebrafish cell lines are highly attractive to investigate cell biology and zebrafish cell lines complement the experimental tools that are available already. We established a straightforward method to culture cells from a single zebrafish embryo or a single tumor. Here we describe the generation of fibroblast-like cell lines from wild-type and ptenb(-/-) embryos and an endothelial-like cell line from a tumor of an adult ptena(+/-)ptenb(-/-) zebrafish. This protocol can easily be adapted to establish stable cell lines from any mutant or transgenic zebrafish line and the average time to obtain a pro-stable cell line is 3-5 months.

  6. Recombinant protein production from stable mammalian cell lines and pools.

    Science.gov (United States)

    Hacker, David L; Balasubramanian, Sowmya

    2016-06-01

    We highlight recent developments for the production of recombinant proteins from suspension-adapted mammalian cell lines. We discuss the generation of stable cell lines using transposons and lentivirus vectors (non-targeted transgene integration) and site-specific recombinases (targeted transgene integration). Each of these methods results in the generation of cell lines with protein yields that are generally superior to those achievable through classical plasmid transfection that depends on the integration of the transfected DNA by non-homologous DNA end-joining. This is the main reason why these techniques can also be used for the generation of stable cell pools, heterogenous populations of recombinant cells generated by gene delivery and genetic selection without resorting to single cell cloning. This allows the time line from gene transfer to protein production to be reduced.

  7. Establishment of human embryonic stem cell line from gamete donors

    Institute of Scientific and Technical Information of China (English)

    LI Tao; ZHOU Can-quan; MAI Qing-yun; ZHUANG Guang-lun

    2005-01-01

    Background Human embryonic stem (HES) cell derived from human blastocyst can be propagated indefinitely in the primitive undifferentiated state while remaining pluripotent. It has exciting potential in human developmental biology, drug discovery, and transplantation medicine. But there are insufficient HES cell lines for further study. Methods Three oocyte donors were studied, and 3 in vitro fertilization (IVF) cycles were carried out to get blastocysts for the establishment of HES cell line. Isolated from blastocysts immunosurgically, inner cell mass (ICM) was cultured and propagated on mouse embryonic fibroblasts (MEFs). Once established, morphology, cell surface markers, karyotype and differentiating ability of the cell line were thoroughly analyzed.Results Four ICMs from 7 blastocysts were cultured on MEFs. After culture, one cell line (cHES-1) was established and met the criteria for defining human pluripotent stem cells including a series of markers used to identify pluripotent stem cells, morphological similarity to primate embryonic stem cells and HES reported else where. Normal and stable karyotype maintained over 60 passages, and demonstrated ability to differentiate into a wide variety of cell types.Conclusions HES cell lines can be established from gamete donors at a relatively highly efficient rate. The establishment will exert a widespread impact on biomedical research.

  8. Susceptibility of various cell lines to Neospora caninum tachyzoites cultivation

    Directory of Open Access Journals (Sweden)

    Khordadmehr, M.,

    2014-05-01

    Full Text Available Neospora caninum is a coccidian protozoan parasite which is a major cause of bovine abortions and neonatal mortality in cattle, sheep, goat and horse. Occasionally, cultured cells are used for isolation and multiplication of the agent in vitro with several purposes. In this study the tachyzoite yields of N. caninum were compared in various cell cultures as the host cell lines. Among the cell cultures tested, two presented good susceptibility to the agent: cell lines Vero and MA-104. SW742 and TLI (in vitro suspension culture of lymphoid cells infected with Theileria lestoquardi showed moderate sensitivity. No viable tachyzoite were detected in the culture of MDCK and McCoy cell lines. These results demonstrate that MA-104 and SW742 cells present adequate susceptibility to N. caninum compared to Vero cells, which have been largely used to multiply the parasite in vitro. Moreover, these have easy manipulation, fast multiplication and relatively low nutritional requirements. In addition, the result of this study showed that TLI cell line as a suspension cell culture is susceptible to Nc-1 tachyzoites infection and could be used as an alternative host cell line for tachyzoites culture in vitro studies.

  9. JKT-1 is not a human seminoma cell line.

    Science.gov (United States)

    de Jong, Jeroen; Stoop, Hans; Gillis, Ad J M; van Gurp, Ruud J H L M; van Drunen, Ellen; Beverloo, H Berna; Lau, Yun-Fai Chris; Schneider, Dominik T; Sherlock, Jon K; Baeten, John; Hatakeyama, Shingo; Ohyama, Chikara; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2007-08-01

    The JKT-1 cell line has been used in multiple independent studies as a representative model of human testicular seminoma. However, no cell line for this specific tumour type has been independently confirmed previously; and therefore, the seminomatous origin of JKT-1 must be proven. The genetic constitution of the JKT-1 cells was determined using flow cytometry and spectral karyotyping, as well as array comparative genomic hybridization and fluorescent in situ hybridization. Marker profiling, predominantly based on differentially expressed proteins during normal germ cell development, was performed by immunohistochemistry and Western blot analyses. Moreover, genome wide affymetrix mRNA expression and profiling of 157 microRNAs was performed, and the status of genomic imprinting was determined. A germ cell origin of the JKT-1 cells was in line with genomic imprinting status and marker profile (including positive staining for several cancer-testis antigens). However, the supposed primary tumour, from which the cell line was derived, being indeed a classical seminoma, was molecularly proven not to be the origin of the cell line. The characteristic chromosomal anomalies of seminoma, e.g. gain of the short arm of chromosome 12, as well as the informative marker profile (positive staining for OCT3/4, NANOG, among others) were absent in the various JKT-1 cell lines investigated, irrespective of where the cells were cultured. All results indicate that the JKT-1 cell line is not representative of human seminoma. Although it can originate from an early germ cell, a non-germ cell derivation cannot be excluded.

  10. Investigation of radiosensitivity gene signatures in cancer cell lines.

    Directory of Open Access Journals (Sweden)

    John S Hall

    Full Text Available Intrinsic radiosensitivity is an important factor underlying radiotherapy response, but there is no method for its routine assessment in human tumours. Gene signatures are currently being derived and some were previously generated by expression profiling the NCI-60 cell line panel. It was hypothesised that focusing on more homogeneous tumour types would be a better approach. Two cell line cohorts were used derived from cervix [n = 16] and head and neck [n = 11] cancers. Radiosensitivity was measured as surviving fraction following irradiation with 2 Gy (SF2 by clonogenic assay. Differential gene expression between radiosensitive and radioresistant cell lines (SF2 median was investigated using Affymetrix GeneChip Exon 1.0ST (cervix or U133A Plus2 (head and neck arrays. There were differences within cell line cohorts relating to tissue of origin reflected by expression of the stratified epithelial marker p63. Of 138 genes identified as being associated with SF2, only 2 (1.4% were congruent between the cervix and head and neck carcinoma cell lines (MGST1 and TFPI, and these did not partition the published NCI-60 cell lines based on SF2. There was variable success in applying three published radiosensitivity signatures to our cohorts. One gene signature, originally trained on the NCI-60 cell lines, did partially separate sensitive and resistant cell lines in all three cell line datasets. The findings do not confirm our hypothesis but suggest that a common transcriptional signature can reflect the radiosensitivity of tumours of heterogeneous origins.

  11. Development of a cell line from Echinococcus granulosus germinal layer.

    Science.gov (United States)

    Albani, Clara María; Cumino, Andrea Carina; Elissondo, María Celina; Denegri, Guillermo María

    2013-10-01

    In vitro culture of parasitic helminths provides an important tool to study cell regeneration and physiology, as well as for molecular biology and genetic engineering studies. In the present study, we established in vitro propagation of cells from Echinococcus granulosus germinal cyst layer. E. granulosus germinal cells grew beyond 100 passages and showed no signs of reduced proliferation capacity. Microscopic analysis revealed that cells grew both attached to the substrate and in suspension, forming three-dimensional structures like mammalian stem cell aggregates. Examination of the chromosome number of attached germinal cells showed a high degree of heteroploidy, suggesting the occurrence of transformation during culture. Monolayer cells survived cryopreservation and were able to proliferate after thawing. Based on the characteristics displayed by E. granulosus germinal cells, we establish a cell line from the E. granulosus germinal layer. Furthermore, we propose that this cell line could be useful for drug screening and for obtaining parasite material.

  12. Establishment of Jurkat tet-on cell line

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Tet-control system is developed to tightly control target gene expression in mammalian cells by using the regulatory elements of tetracycline-repressor of the transposor Tn10 from E.Coli.We have transfected reverse tetracycline-controlled transactivator gene (rtTA) into genome of Jurkat cells and established two Jurkat tet-on cell lines.Induction of luciferase reporter activity with doxycycline,a tetracycline derivative,is dose-dependent with a peak value of 32-fold increment.Establishment of Jurkat tet-on cell lines greatly facilitates quantitative studies on target gene functions in the cells.

  13. Establishment and characterization of rat portal myofibroblast cell lines.

    Directory of Open Access Journals (Sweden)

    Michel Fausther

    Full Text Available The major sources of scar-forming myofibroblasts during liver fibrosis are activated hepatic stellate cells (HSC and portal fibroblasts (PF. In contrast to well-characterized HSC, PF remain understudied and poorly defined. This is largely due to the facts that isolation of rodent PF for functional studies is technically challenging and that PF cell lines had not been established. To address this, we have generated two polyclonal portal myofibroblast cell lines, RGF and RGF-N2. RGF and RGF-N2 were established from primary PF isolated from adult rat livers that underwent culture activation and subsequent SV40-mediated immortalization. Specifically, Ntpdase2/Cd39l1-sorted primary PF were used to generate the RGF-N2 cell line. Both cell lines were functionally characterized by RT-PCR, immunofluorescence, immunoblot and bromodeoxyuridine-based proliferation assay. First, immortalized RGF and RGF-N2 cells are positive for phenotypic myofibroblast markers alpha smooth muscle actin, type I collagen alpha-1, tissue inhibitor of metalloproteinases-1, PF-specific markers elastin, type XV collagen alpha-1 and Ntpdase2/Cd39l1, and mesenchymal cell marker ecto-5'-nucleotidase/Cd73, while negative for HSC-specific markers desmin and lecithin retinol acyltransferase. Second, both RGF and RGF-N2 cell lines are readily transfectable using standard methods. Finally, RGF and RGF-N2 cells attenuate the growth of Mz-ChA-1 cholangiocarcinoma cells in co-culture, as previously demonstrated for primary PF. Immortalized rat portal myofibroblast RGF and RGF-N2 cell lines express typical markers of activated PF-derived myofibroblasts, are suitable for DNA transfection, and can effectively inhibit cholangiocyte proliferation. Both RGF and RGF-N2 cell lines represent novel in vitro cellular models for the functional studies of portal (myofibroblasts and their contribution to the progression of liver fibrosis.

  14. Mercury specifically induces LINE-1 activity in a human neuroblastoma cell line.

    Science.gov (United States)

    Habibi, Laleh; Shokrgozar, Mohammad Ali; Tabrizi, Mina; Modarressi, Mohammad Hossein; Akrami, Seyed Mohammad

    2014-01-01

    L1 retro-elements comprise 17% of the human genome. Approximately 100 copies of these autonomous mobile elements are active in our DNA and can cause mutations, gene disruptions, and genomic instability. Therefore, human cells control the activities of L1 elements, in order to prevent their deleterious effects through different mechanisms. However, some toxic agents increase the retrotransposition activity of L1 elements in somatic cells. In order to identify specific effects of neurotoxic metals on L1 activity in neuronal cells, we studied the effects of mercury and cobalt on L1-retroelement activity by measuring levels of cellular transcription, protein expression, and genomic retrotransposition in a neuroblastoma cell line compared with the effects in three non-neuronal cell lines. Our results show that mercury increased the expression of L1 RNA, the activity of the L1 5'UTR, and L1 retrotransposition exclusively in the neuroblastoma cell line but not in non-neuronal cell lines. However, cobalt increased the expression of L1 RNA in neuroblastoma cells, HeLa cells, and wild-type human fibroblasts, and also increased the activity of the L1 5'UTR as well as the SV40 promoter in HeLa cells but not in neuroblastoma cells. Exposure to cobalt did not result in increased retrotransposition activity in HeLa cells or neuroblastoma cells. We conclude that non-toxic levels of the neurotoxic agent mercury could influence DNA by increasing L1 activities, specifically in neuronal cells, and may make these cells susceptible to neurodegeneration over time.

  15. Apoptotic effect of noscapine in breast cancer cell lines.

    Science.gov (United States)

    Quisbert-Valenzuela, Edwin O; Calaf, Gloria M

    2016-06-01

    Cancer is a public health problem in the world and breast cancer is the most frequently cancer in women. Approximately 15% of the breast cancers are triple-negative. Apoptosis regulates normal growth, homeostasis, development, embryogenesis and appropriate strategy to treat cancer. Bax is a protein pro-apoptotic enhancer of apoptosis in contrast to Bcl-2 with antiapoptotic properties. Initiator caspase-9 and caspase-8 are features of intrinsic and extrinsic apoptosis pathway, respectively. NF-κB is a transcription factor known to be involved in the initiation and progression of breast cancer. Noscapine, an alkaloid derived from opium is used as antitussive and showed antitumor properties that induced apoptosis in cancer cell lines. The aim of the present study was to determine the apoptotic effect of noscapine in breast cancer cell lines compared to breast normal cell line. Three cell lines were used: i) a control breast cell line MCF-10F; ii) a luminal-like adenocarcinoma triple-positive breast cell line MCF-7; iii) breast cancer triple-negative cell line MDA-MB-231. Our results showed that noscapine had lower toxicity in normal cells and was an effective anticancer agent that induced apoptosis in breast cancer cells because it increases Bax gene and protein expression in three cell lines, while decreases Bcl-xL gene expression, and Bcl-2 protein expression decreased in breast cancer cell lines. Therefore, Bax/Bcl-2 ratio increased in the three cell lines. This drug increased caspase-9 gene expression in breast cancer cell lines and caspase-8 gene expression increased in MCF-10F and MDA-MB-231. Furthermore, it increased cleavage of caspase-8, suggesting that noscapine-induced apoptosis is probably due to the involvement of extrinsic and intrinsic apoptosis pathways. Antiapoptotic gene and protein expression diminished and proapoptotic gene and protein expression increased noscapine-induced expression, probably due to decrease in NF-κB gene and protein expression

  16. Differential effects of bisphosphonates on breast cancer cell lines

    NARCIS (Netherlands)

    Verdijk, R.; Franke, H.R.; Wolbers, F.; Vermes, I.

    2007-01-01

    Bisphosphonates may induce direct anti-tumor effects in breast cancers cells in virtro. In this study, six bisphosphonates were administered to three breast caner cell lines. Cell proliferation was measured by quantification of th expressio of Cyclin D1 mRNA. Apoptosis was determined by flow cytome

  17. 6-C-methyl flavonoids isolated from Pinus densata inhibit the proliferation and promote the apoptosis of the HL-60 human promyelocytic leukaemia cell line.

    Science.gov (United States)

    Yue, Rongcai; Li, Bo; Shen, Yunheng; Zeng, Huawu; Li, Bo; Yuan, Hu; He, Yiren; Shan, Lei; Zhang, Weidong

    2013-08-01

    Three structurally related 6-C-methyl flavonoids isolated from Pinus densata, including 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone (PD1), 5,7,4'-trihydroxy-3,8-dimethoxy-6-C-methylflavone (PD2), and 5,7,4'-trihydroxy-3-methoxy-6-C-methylflavone (PD3), were tested for their ability to inhibit the proliferation and promote the apoptosis of the HL-60 human leukaemia cell line. Cytotoxicity assays in the HL-60 human cancer cell line demonstrated that 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone exhibited the most potent cytotoxicity of the three structurally related 6-C-methyl flavonoids. 5,4'-Dihydroxy-3,7,8-trimethoxy-6-C-methylflavone inhibited the proliferation of HL-60 cells in a dose-dependent manner with an IC₅₀ of 7.91 µM (48 h treatment). Furthermore, 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone-induced apoptosis was associated with mitochondrial membrane disruption and cytochome c release. Flow cytometry analyses revealed an increase in the hypodiploid population in 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone-treated HL-60 cells. Treatment with a concentration of 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone that induced apoptosis activated caspase-3 but did not activate caspase-1. A caspase-3 inhibitor (Ac-DEVD-CHO), but not a caspase-1 inhibitor (Ac-YVAD-CHO), reversed the cytotoxic effects of 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone in HL-60 cells. These data demonstrated that 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone effectively induced the apoptosis of HL-60 cells and exhibited significant anticancer activity via the mitochondrial caspase-3-dependent apoptosis pathway.

  18. Construction of anti-VEGFR-2 IgG1 like human antibody and its expression in CHO-k cells%抗VEGFR-2全人源IgG1抗体的构建及其在CHO-k细胞中的表达

    Institute of Scientific and Technical Information of China (English)

    李致科; 何远; 张娟; 解伟; 曹婉璐; 王泽根; 王旻

    2013-01-01

    本文在实验室构建的单链抗体-Fc融合抗体[scFv(AK404R)-Fc]的基础上构建抗VEGFR-2全人源IgG1样全长抗体(Mab-04).利用重叠PCR,获得Mab-04的轻链和重链的核酸序列后分别克隆到真核表达载体pcDNA3.1,获得重组质粒.脂质体法将重组质粒转染至CHO-k细胞,经ProteinA柱纯化细胞培养上清液获得目的蛋白,利用Western blotting检测目的蛋白,ELISA检测Mab-04与抗原亲和力.测序表明重组质粒构建成功,Westem blotting检测显示目的蛋白成功表达(1μg.mL-1),ELISA检测阐明该抗体能与抗原结合并呈浓度依赖性(IC50为50 nmol.L-1),表明Mab-04成功表达并正确装配,为进一步大量制备该抗体及其活性研究打下基础.

  19. Structure-mutagenicity analysis with the CHO/HGPRT system

    Energy Technology Data Exchange (ETDEWEB)

    Hsie, A.W.

    1981-01-01

    Using a mammalian cell gene mutational assay, the Chinese hamster ovary cell/hyposanthine-guanine phosphoribosyl transferase (CHO/HGPRT) system, we have studied the structure-mutagenicity of ten alkylating agents and six platinum(II) chlorammines. In analyzing the mutagenesis data, we describe the mutagenic activity as the number of mutants per 10/sup 6/ clonable cells induced by a 1 ..mu..M concentration of chemical tested. The mutagenicity of alkylating chemicals decreases with increasing size of the alky group; methylating agents are three to six times more mutagenic than the corresponding ethylating agents, cis-Pt(NH/sub 3/)/sub 2/Cl/sub 2/ is mutagenic, but its steric isomer, trans-Pr(NH/sub 2/)/sub 2/Cl/sub 2/, is very much less mutagenic. These results, together with determination of chemically induced DNA lesions permit analyses of certain aspects of mechanisms of chemical mutagensis.

  20. Investigation of the selenium metabolism in cancer cell lines.

    Science.gov (United States)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan; Andresen, Lars; Skov, Søren; Gammelgaard, Bente

    2011-02-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 μM were incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein binding. Correlations between cell death induction and the Se compounds transformations could not be demonstrated.

  1. Global Conservation of Protein Status between Cell Lines and Xenografts

    Directory of Open Access Journals (Sweden)

    Julian Biau

    2016-08-01

    Full Text Available Common preclinical models for testing anticancer treatment include cultured human tumor cell lines in monolayer, and xenografts derived from these cell lines in immunodeficient mice. Our goal was to determine how similar the xenografts are compared with their original cell line and to determine whether it is possible to predict the stability of a xenograft model beforehand. We studied a selection of 89 protein markers of interest in 14 human cell cultures and respective subcutaneous xenografts using the reverse-phase protein array technology. We specifically focused on proteins and posttranslational modifications involved in DNA repair, PI3K pathway, apoptosis, tyrosine kinase signaling, stress, cell cycle, MAPK/ERK signaling, SAPK/JNK signaling, NFκB signaling, and adhesion/cytoskeleton. Using hierarchical clustering, most cell culture-xenograft pairs cluster together, suggesting a global conservation of protein signature. Particularly, Akt, NFkB, EGFR, and Vimentin showed very stable protein expression and phosphorylation levels highlighting that 4 of 10 pathways were highly correlated whatever the model. Other proteins were heterogeneously conserved depending on the cell line. Finally, cell line models with low Akt pathway activation and low levels of Vimentin gave rise to more reliable xenograft models. These results may be useful for the extrapolation of cell culture experiments to in vivo models in novel targeted drug discovery.

  2. Phenotypes and karyotypes of human malignant mesothelioma cell lines.

    Directory of Open Access Journals (Sweden)

    Vandana Relan

    Full Text Available BACKGROUND: Malignant mesothelioma is an aggressive tumour of serosal surfaces most commonly pleura. Characterised cell lines represent a valuable tool to study the biology of mesothelioma. The aim of this study was to develop and biologically characterise six malignant mesothelioma cell lines to evaluate their potential as models of human malignant mesothelioma. METHODS: Five lines were initiated from pleural biopsies, and one from pleural effusion of patients with histologically proven malignant mesothelioma. Mesothelial origin was assessed by standard morphology, Transmission Electron Microscopy (TEM and immunocytochemistry. Growth characteristics were assayed using population doubling times. Spectral karyotyping was performed to assess chromosomal abnormalities. Authentication of donor specific derivation was undertaken by DNA fingerprinting using a panel of SNPs. RESULTS: Most of cell lines exhibited spindle cell shape, with some retaining stellate shapes. At passage 2 to 6 all lines stained positively for calretinin and cytokeratin 19, and demonstrated capacity for anchorage-independent growth. At passage 4 to 16, doubling times ranged from 30-72 hours, and on spectral karyotyping all lines exhibited numerical chromosomal abnormalities ranging from 41 to 113. Monosomy of chromosomes 8, 14, 22 or 17 was observed in three lines. One line displayed four different karyotypes at passage 8, but only one karyotype at passage 42, and another displayed polyploidy at passage 40 which was not present at early passages. At passages 5-17, TEM showed characteristic features of mesothelioma ultrastructure in all lines including microvilli and tight intercellular junctions. CONCLUSION: These six cell lines exhibit varying cell morphology, a range of doubling times, and show diverse passage-dependent structural chromosomal changes observed in malignant tumours. However they retain characteristic immunocytochemical protein expression profiles of

  3. Pathway-specific differences between tumor cell lines and normal and tumor tissue cells

    Directory of Open Access Journals (Sweden)

    Tozeren Aydin

    2006-11-01

    Full Text Available Abstract Background Cell lines are used in experimental investigation of cancer but their capacity to represent tumor cells has yet to be quantified. The aim of the study was to identify significant alterations in pathway usage in cell lines in comparison with normal and tumor tissue. Methods This study utilized a pathway-specific enrichment analysis of publicly accessible microarray data and quantified the gene expression differences between cell lines, tumor, and normal tissue cells for six different tissue types. KEGG pathways that are significantly different between cell lines and tumors, cell lines and normal tissues and tumor and normal tissue were identified through enrichment tests on gene lists obtained using Significance Analysis of Microarrays (SAM. Results Cellular pathways that were significantly upregulated in cell lines compared to tumor cells and normal cells of the same tissue type included ATP synthesis, cell communication, cell cycle, oxidative phosphorylation, purine, pyrimidine and pyruvate metabolism, and proteasome. Results on metabolic pathways suggested an increase in the velocity nucleotide metabolism and RNA production. Pathways that were downregulated in cell lines compared to tumor and normal tissue included cell communication, cell adhesion molecules (CAMs, and ECM-receptor interaction. Only a fraction of the significantly altered genes in tumor-to-normal comparison had similar expressions in cancer cell lines and tumor cells. These genes were tissue-specific and were distributed sparsely among multiple pathways. Conclusion Significantly altered genes in tumors compared to normal tissue were largely tissue specific. Among these genes downregulation was a major trend. In contrast, cell lines contained large sets of significantly upregulated genes that were common to multiple tissue types. Pathway upregulation in cell lines was most pronounced over metabolic pathways including cell nucleotide metabolism and oxidative

  4. Biobanking human embryonic stem cell lines

    DEFF Research Database (Denmark)

    Holm, Søren

    2016-01-01

    Stem cell banks curating and distributing human embryonic stem cells have been established in a number of countries and by a number of private institutions. This paper identifies and critically discusses a number of arguments that are used to justify the importance of such banks in policy...... are curiously absent from the particular stem cell banking policy discourse. This to some extent artificially isolates this discourse from the broader discussions about the flows of reproductive materials and tissues in modern society, and such isolation may lead to the interests of important actors being...

  5. Cold storage and cryopreservation of tick cell lines

    Directory of Open Access Journals (Sweden)

    Lallinger Gertrud

    2010-04-01

    Full Text Available Abstract Background Tick cell lines are now available from fifteen ixodid and argasid species of medical and veterinary importance. However, some tick cell lines can be difficult to cryopreserve, and improved protocols for short- and long-term low temperature storage will greatly enhance their use as tools in tick and tick-borne pathogen research. In the present study, different protocols were evaluated for cold storage and cryopreservation of tick cell lines derived from Rhipicephalus (Boophilus decoloratus, Rhipicephalus (Boophilus microplus, Ixodes ricinus and Ixodes scapularis. For short-term cold storage, cells were kept under refrigeration at 6°C for 15, 30 and 45 days. For cryopreservation in liquid nitrogen, use of a sucrose-phosphate-glutamate freezing buffer (SPG as cryoprotectant was compared with dimethylsulfoxide (DMSO supplemented with sucrose. Cell viability was determined by the trypan blue exclusion test and cell morphology was evaluated in Giemsa-stained cytocentrifuge smears. Results Cold storage at 6°C for up to 30 days was successful in preserving R. (B. microplus, R. (B. decoloratus, I. ricinus and I. scapularis cell lines; lines from the latter three species could be easily re-cultivated after 45 days under refrigeration. While cell lines from all four tick species cryopreserved with 6% DMSO were successfully resuscitated, the R. (B. decoloratus cells did not survive freezing in SPG and of the other three species, only the R. (B. microplus cells resumed growth during the observation period. Conclusions This constitutes the first report on successful short-term refrigeration of cells derived from R. (B. decoloratus, R. (B. microplus, and I. ricinus, and use of SPG as an alternative to DMSO for cryopreservation, thus making an important contribution to more reliable and convenient tick cell culture maintenance.

  6. Establishment of a new bovine leukosis virus producing cell line.

    Science.gov (United States)

    Beier, D; Riebe, R; Blankenstein, P; Starick, E; Bondzio, A; Marquardt, O

    2004-11-01

    Due to the prevalence of different bovine leukosis virus (BLV) species in the cattle population in Europe, problems may arise in the serological diagnosis of BLV infections. In addition, earlier investigations demonstrated that contamination of the BLV antigen-producing cell culture systems by bovine viral diarrhea virus (BVDV) may give rise to misinterpretation of serological test results after BVDV vaccination of cattle. By co-cultivation of peripheral leukocytes of a BLV-infected cow with a permanent sheep kidney cell line, a new BLV-producing cell line named PO714 was established. This line carries a BLV provirus of the Belgian species and has been tested to be free of a variety of possibly contaminating viruses and mycoplasms. Investigations of a panel of well-characterised sera by agar gel immunodiffusion (AGID) and capture ELISA (cELISA) tests using antigen prepared from this new cell line in comparison with antigen of the well-known cell line FLK/BLV yielded comparable results. False positive results caused by BVDV cross-reactions could be eliminated when tests were carried out with antigen derived from the new cell line.

  7. Expressional patterns of chaperones in ten human tumor cell lines

    Directory of Open Access Journals (Sweden)

    Slavc Irene

    2004-12-01

    Full Text Available Abstract Background Chaperones (CH play an important role in tumor biology but no systematic work on expressional patterns has been reported so far. The aim of the study was therefore to present an analytical method for the concomitant determination of several CH in human tumor cell lines, to generate expressional patterns in the individual cell lines and to search for tumor and non-tumor cell line specific CH expression. Human tumor cell lines of neuroblastoma, colorectal and adenocarcinoma of the ovary, osteosarcoma, rhabdomyosarcoma, malignant melanoma, lung, cervical and breast cancer, promyelocytic leukaemia were homogenised, proteins were separated on two-dimensional gel electrophoresis with in-gel digestion of proteins and MALDI-TOF/TOF analysis was carried out for the identification of CH. Results A series of CH was identified including the main CH groups as HSP90/HATPas_C, HSP70, Cpn60_TCP1, DnaJ, Thioredoxin, TPR, Pro_isomerase, HSP20, ERP29_C, KE2, Prefoldin, DUF704, BAG, GrpE and DcpS. Conclusions The ten individual tumor cell lines showed different expression patterns, which are important for the design of CH studies in tumor cell lines. The results can serve as a reference map and form the basis of a concomitant determination of CH by a protein chemical rather than an immunochemical method, independent of antibody availability or specificity.

  8. Metronidazole decreases viability of DLD-1 colorectal cancer cell line.

    Science.gov (United States)

    Sadowska, Anna; Krętowski, Rafał; Szynaka, Beata; Cechowska-Pasko, Marzanna; Car, Halina

    2013-10-01

    The aim of our study was to evaluate the impact of metronidazole (MTZ) on DLD-1 colorectal cancer cell (CRC) line. Toxicity of MTZ was determined by MTT test. Cells were incubated with MTZ used in different concentrations for 24, 48, and 72 hours. The effect of MTZ on DNA synthesis was measured as [3H]-thymidine incorporation. The morphological changes in human DLD-1 cell line were defined by transmission electron microscope OPTON 900. The influence of MTZ on the apoptosis of DLD-1 cell lines was detected by flow cytometry and fluorescence microscopy, while cell concentration, volume, and diameter were displayed by Scepter Cell Counter from Millipore. Our results show that cell viability was diminished in all experimental groups in comparison with the control, and the differences were statistically significant. We did not find any significant differences in [3H]-thymidine incorporation in all experimental groups and times of observation. Cytofluorimetric assays demonstrated a statistically significant increase of apoptotic rate in MTZ concentrations 10 and 50 μg/mL after 24 hours; 0.1, 10, 50, and 250 μg/mL after 48 hours; and in all concentrations after 72 hours compared with control groups. In the ultrastructural studies, necrotic or apoptotic cells were occasionally seen. In conclusion, MTZ affects human CRC cell line viability. The reduction of cell viability was consistent with the apoptotic test.

  9. In vitro radiosensitivity of human leukemia cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Weichselbaum, R.R.; Greenberger, J.S.; Schmidt, A.; Karpas, A.; Moloney, W.C.; Little, J.B.

    1981-05-01

    The in vitro radiobiologic survival values (n, D0) of four tumor lines derived from human hematopoietic tumors were studied. These cell lines were HL50 (n . 1.3, D0 . 117 rad(1.17 Gy)), promyelocytic leukemia; K562 (n . 1.4, D0 . 165 rad(1.65 Gy)), erythroleukemia; 45 (n . 1.1, D0 . 147 rad(1.47 Gy)), acute lymphocyte leukemia; and 176 (n . 4.0, D0 . 76 rad(0.76 Gy)), acute monomyelogenous leukemia. More cell lines must be examined before the exact relationship between in vitro radiosensitivity and clinical radiocurability is firmly established.

  10. Effect of failures and repairs on multiple cell production lines

    Energy Technology Data Exchange (ETDEWEB)

    Legato, P.; Bobbio, A.; Roberti, L.

    1989-01-01

    This paper examines a production line composed of multiple stages, or cells, which are passed in sequential order to arrive to the final product. Two possible coordination disciplines are considered, namely: the classical tandem arrangement of sequential working centers with input buffer and the kanban scheme, considered the Japanese shop floor realization of the Just-In-Time (JIT) manifacturing approach. The production line is modelled and analysed by means of Stochastic Petri Nets (SPN). Finally an analysis is made of the possibility that the working cells can incur failure/repair cycles perturbing the production flow of the line and thus reduce performance indices.

  11. Efficacy of ribavirin against malignant glioma cell lines

    Science.gov (United States)

    OGINO, AKIYOSHI; SANO, EMIKO; OCHIAI, YUSHI; YAMAMURO, SHUN; TASHIRO, SHINYA; YACHI, KAZUNARI; OHTA, TAKASHI; FUKUSHIMA, TAKAO; OKAMOTO, YUTAKA; TSUMOTO, KOUHEI; UEDA, TAKUYA; YOSHINO, ATSUO; KATAYAMA, YOICHI

    2014-01-01

    Ribavirin (1-β-D-ribofuranosy-1,2,4-triazole-3-carboxamide) has been widely administered as an antiviral agent against RNA and DNA viruses. Ribavirin, in combination with interferon, has predominantly been applied in the treatment of the hepatitis C virus infection and its potential antitumor efficacy has recently become a point of interest. The aim of the present study was to evaluate the effect of ribavirin on the growth of malignant glioma cells, to identify novel predictive genes in malignant glioma cells (by analyzing gene expression profiles) and to assess the influence of ribavirin on the cell cycle of malignant glioma cells. The present study evaluated the antitumor efficacy of ribavirin against various malignant glioma cell lines (A-172, AM-38, T98G, U-87MG, U-138MG, U-251MG and YH-13). After culturing the cells in ribavirin-containing culture medium (final concentration, 0–1,000 μM) for 72 h, the viable proliferated cells were harvested and counted. The half maximal inhibitory concentration of ribavirin, with regard to the growth of the malignant glioma cell lines, was determined from the concentration of ribavirin required for 50% growth inhibition in comparison to the untreated control cells. Furthermore, the current study identified the genes in which the gene expression levels correlated with the ribavirin sensitivity of the malignant glioma cells lines, using a high-density oligonucleotide array. Finally, cell cycle analysis was performed on the U-87MG cell line. It was identified that ribavirin inhibited the growth of all of the malignant glioma cell lines in a dose-dependent manner, although the ribavirin sensitivity varied between each cell line. Of the extracted genes, PDGFRA demonstrated the strongest positive correlation between gene expression level and ribavirin sensitivity. Cell cycle analysis of the U-87MG cell line demonstrated that ribavirin treatment induces G0/G1 arrest and thus may be an effective agent for inhibiting malignant

  12. Comparative analysis of cell death induction by Taurolidine in different malignant human cancer cell lines

    Directory of Open Access Journals (Sweden)

    Ritter Peter R

    2010-03-01

    Full Text Available Abstract Background Taurolidine (TRD represents an anti-infective substance with anti-neoplastic activity in many malignant cell lines. So far, the knowledge about the cell death inducing mechanisms and pathways activated by TRD is limited. The aim of this study was therefore, to perform a comparative analysis of cell death induction by TRD simultaneously in different malignant cell lines. Materials and methods Five different malignant cell lines (HT29/Colon, Chang Liver/Liver, HT1080/fibrosarcoma, AsPC-1/pancreas and BxPC-3/pancreas were incubated with increasing concentrations of TRD (100 μM, 250 μM and 1000 μM for 6 h and 24 h. Cell viability, apoptosis and necrosis were analyzed by FACS analysis (Propidiumiodide/AnnexinV staining. Additionally, cells were co-incubated with the caspase Inhibitor z-VAD, the radical scavenger N-Acetylcystein (NAC and the Gluthation depleting agent BSO to examine the contribution of caspase activation and reactive oxygen species in TRD induced cell death. Results All cell lines were susceptible to TRD induced cell death without resistance toward this anti-neoplastic agent. However, the dose response effects were varying largely between different cell lines. The effect of NAC and BSO co-treatment were highly different among cell lines - suggesting a cell line specific involvement of ROS in TRD induced cell death. Furthermore, impact of z-VAD mediated inhibition of caspases was differing strongly among the cell lines. Conclusion This is the first study providing a simultaneous evaluation of the anti-neoplastic action of TRD across several malignant cell lines. The involvement of ROS and caspase activation was highly variable among the five cell lines, although all were susceptible to TRD induced cell death. Our results indicate, that TRD is likely to provide multifaceted cell death mechanisms leading to a cell line specific diversity.

  13. Exometabolom analysis of breast cancer cell lines: Metabolic signature.

    Science.gov (United States)

    Willmann, Lucas; Erbes, Thalia; Halbach, Sebastian; Brummer, Tilman; Jäger, Markus; Hirschfeld, Marc; Fehm, Tanja; Neubauer, Hans; Stickeler, Elmar; Kammerer, Bernd

    2015-08-21

    Cancer cells show characteristic effects on cellular turnover and DNA/RNA modifications leading to elevated levels of excreted modified nucleosides. We investigated the molecular signature of different subtypes of breast cancer cell lines and the breast epithelial cell line MCF-10A. Prepurification of cell culture supernatants was performed by cis-diol specific affinity chromatography using boronate-derivatized polyacrylamide gel. Samples were analyzed by application of reversed phase chromatography coupled to a triple quadrupole mass spectrometer. Collectively, we determined 23 compounds from RNA metabolism, two from purine metabolism, five from polyamine/methionine cycle, one from histidine metabolism and two from nicotinate and nicotinamide metabolism. We observed major differences of metabolite excretion pattern between the breast cancer cell lines and MCF-10A, just as well as between the different breast cancer cell lines themselves. Differences in metabolite excretion resulting from cancerous metabolism can be integrated into altered processes on the cellular level. Modified nucleosides have great potential as biomarkers in due consideration of the heterogeneity of breast cancer that is reflected by the different molecular subtypes of breast cancer. Our data suggests that the metabolic signature of breast cancer cell lines might be a more subtype-specific tool to predict breast cancer, rather than a universal approach.

  14. Biobanking human embryonic stem cell lines

    DEFF Research Database (Denmark)

    Holm, Søren

    2016-01-01

    are curiously absent from the particular stem cell banking policy discourse. This to some extent artificially isolates this discourse from the broader discussions about the flows of reproductive materials and tissues in modern society, and such isolation may lead to the interests of important actors being...

  15. Characterisation of thyroid medullary carcinoma TT cell line.

    Science.gov (United States)

    Zabel, M; Grzeszkowiak, J

    1997-01-01

    TT cell line is the best known stabilized cell line derived from the human medullary thyroid carcinoma. The ultrastructural characteristics of these cells include well developed rough endoplasmic reticulum, a prominent Golgi apparatus and a considerable number of secretory granules. Numerous hormones were immunocytochemically demonstrated in TT cells of which calcitonin and calcitonin gene-related peptide (CGRP) are the products of the same gene but an alternative RNA processing. TT cells were found to produce some other hormones as well, namely ACTH, neurotensin, enkephalin, PTHrP, gastrin-releasing peptide (GRP), serotonin but also functional proteins of the chromogranin group, synaptophysin, NSE, calbindin and tyrosine hydroxylase. Some marker proteins have been detected in the cytosol (CEA) and in the cytoskeleton (alpha-tubulin, cytokeratin). The influence of numerous factors on the secretory activity of these cells has been demonstrated so far, including effects of 1,25-dihydroxycholecalciferol, glucocorticoids, sex steroids, cAMP, gastrin-releasing peptide, sodium butyrate, phorbol esters, ionomycin and forskolin. The investigators performed on the TT cell line demonstrate that this is the most reliable model system for the human parafollicular cells developed so far, in comparison to other cell lines derived from the medullary carcinoma of the thyroid.

  16. Neurohypophysial Receptor Gene Expression by Thymic T Cell Subsets and Thymic T Cell Lymphoma Cell Lines

    Directory of Open Access Journals (Sweden)

    I. Hansenne

    2004-01-01

    transcribed in thymic epithelium, while immature T lymphocytes express functional neurohypophysial receptors. Neurohypophysial receptors belong to the G protein-linked seven-transmembrane receptor superfamily and are encoded by four distinct genes, OTR, V1R, V2R and V3R. The objective of this study was to identify the nature of neurohypophysial receptor in thymic T cell subsets purified by immunomagnetic selection, as well as in murine thymic lymphoma cell lines RL12-NP and BW5147. OTR is transcribed in all thymic T cell subsets and T cell lines, while V3R transcription is restricted to CD4+ CD8+ and CD8+ thymic cells. Neither V1R nor V2R transcripts are detected in any kind of T cells. The OTR protein was identified by immunocytochemistry on thymocytes freshly isolated from C57BL/6 mice. In murine fetal thymic organ cultures, a specific OTR antagonist does not modify the percentage of T cell subsets, but increases late T cell apoptosis further evidencing the involvement of OT/OTR signaling in the control of T cell proliferation and survival. According to these data, OTR and V3R are differentially expressed during T cell ontogeny. Moreover, the restriction of OTR transcription to T cell lines derived from thymic lymphomas may be important in the context of T cell leukemia pathogenesis and treatment.

  17. Toward genome-scale models of the Chinese hamster ovary cells: incentives, status and perspectives

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder; Fan, Yuzhou; Weilguny, Dietmar;

    2014-01-01

    Bioprocessing of the important Chinese hamster ovary (CHO) cell lines used for the production of biopharmaceuticals stands at the brink of several redefining events. In 2011, the field entered the genomics era, which has accelerated omics-based phenotyping of the cell lines. In this review we...

  18. Membrane lipidome of an epithelial cell line

    DEFF Research Database (Denmark)

    Sampaio, Julio L; Gerl, Mathias J; Klose, Christian

    2011-01-01

    Tissue differentiation is an important process that involves major cellular membrane remodeling. We used Madin-Darby canine kidney cells as a model for epithelium formation and investigated the remodeling of the total cell membrane lipidome during the transition from a nonpolarized morphology...... to an epithelial morphology and vice versa. To achieve this, we developed a shotgun-based lipidomics workflow that enabled the absolute quantification of mammalian membrane lipidomes with minimal sample processing from low sample amounts. Epithelial morphogenesis was accompanied by a major shift from sphingomyelin...... to glycosphingolipid, together with an increase in plasmalogen, phosphatidylethanolamine, and cholesterol content, whereas the opposite changes took place during an epithelial-to-mesenchymal transition. Moreover, during polarization, the sphingolipids became longer, more saturated, and more hydroxylated as required...

  19. Heterozygous embryonic stem cell lines derived from nonhuman primate parthenotes.

    Science.gov (United States)

    Dighe, Vikas; Clepper, Lisa; Pedersen, Darlene; Byrne, James; Ferguson, Betsy; Gokhale, Sumita; Penedo, M Cecilia T; Wolf, Don; Mitalipov, Shoukhrat

    2008-03-01

    Monoparental parthenotes represent a potential source of histocompatible stem cells that should be isogenic with the oocyte donor and therefore suitable for use in cell or tissue replacement therapy. We generated five rhesus monkey parthenogenetic embryonic stem cell (PESC) lines with stable, diploid female karyotypes that were morphologically indistinguishable from biparental controls, expressed key pluripotent markers, and generated cell derivatives representative of all three germ layers following in vivo and in vitro differentiation. Interestingly, high levels of heterozygosity were observed at the majority of loci that were polymorphic in the oocyte donors. Some PESC lines were also heterozygous in the major histocompatibility complex region, carrying haplotypes identical to those of the egg donor females. Expression analysis revealed transcripts from some imprinted genes that are normally expressed from only the paternal allele. These results indicate that limitations accompanying the potential use of PESC-derived phenotypes in regenerative medicine, including aberrant genomic imprinting and high levels of homozygosity, are cell line-dependent and not always present. PESC lines were derived in high enough yields to be practicable, and their derivatives are suitable for autologous transplantation into oocyte donors or could be used to establish a bank of histocompatible cell lines for a broad spectrum of patients.

  20. Transportation characteristics of nolatrexed in three tumor cell lines

    Institute of Scientific and Technical Information of China (English)

    LI Yi-lei; ZHAO Ai-guo; WU Shu-guang

    2002-01-01

    Objective:To investigate the association of the transportation characteristics of nolatrexed in tumor cells with its drug sensitivity. Methods: The sensitivity of 3 tumor cell lines, C6, SRS82 and LoVo, to nolatrexed were determined by growth inhibition study. After exposure to 20 μmol/L nolatrexed at different time intervals ranging from 0 to 30 min, or to nolatrexed at different concentrations ranging from 0 to 40μmol/L for 10 min, the intracellular drug concentration was measured using high-performance liquid chromatography. Results: C6 was the most sensitive cell line among the three, with sensitivity 6. 8-fold and 13.8-fold those of SRS-82 and LoVo cells respectively. Transportation of nolatrexed in the 3 cell lines were qualitatively similar, which rapidly achieved steady-state within 5 min, and linear relationship between the intracellular and extracellular drug concentration was observed. The intracellular steady-state level achieved in C6 was significantly higher than those in the other two cell lines, the latter having comparable levels. Conclusion: Nolatrexed enters the cell very quickly and different transport capacities are involved in the generation of varied sensitivity to nolatrexed in tumor cells.

  1. Functional bioassays for immune monitoring of high-risk neuroblastoma patients treated with ch14.18/CHO anti-GD2 antibody.

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    Nikolai Siebert

    Full Text Available Effective treatment of high-risk neuroblastoma (NB remains a major challenge in pediatric oncology. Human/mouse chimeric monoclonal anti-GD2 antibody (mAb ch14.18 is emerging as a treatment option to improve outcome. After establishing a production process in Chinese hamster ovary (CHO cells, ch14.18/CHO was made available in Europe for clinical trials. Here, we describe validated functional bioassays for the purpose of immune monitoring of these trials and demonstrate GD2-specific immune effector functions of ch14.18/CHO in treated patients. Two calcein-based bioassays for complement-dependent- (CDC and antibody-dependent cellular cytotoxicity (ADCC were set up based on patient serum and immune cells tested against NB cells. For this purpose, we identified LA-N-1 NB cells as best suited within a panel of cell lines. Assay conditions were first established using serum and cells of healthy donors. We found an effector-to-target (E:T cell ratio of 20:1 for PBMC preparations as best suited for GD2-specific ADCC analysis. A simplified method of effector cell preparation by lysis of erythrocytes was evaluated revealing equivalent results at an E:T ratio of 40:1. Optimal results for CDC were found with a serum dilution at 1:8. For validation, both within-assay and inter-assay precision were determined and coefficients of variation (CV were below 20%. Sample quality following storage at room temperature (RT showed that sodium-heparin-anticoagulated blood and serum are stable for 48 h and 96 h, respectively. Application of these bioassays to blood samples of three selected high-risk NB patients treated with ch14.18/CHO (100 mg/m(2 revealed GD2-specific increases in CDC (4.5-9.4 fold and ADCC (4.6-6.0 fold on day 8 compared to baseline, indicating assay applicability for the monitoring of multicenter clinical trials requiring sample shipment at RT for central lab analysis.

  2. Continuous production of erythropoietin by an established human renal carcinoma cell line: development of the cell line

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, J.B.; Shouval, D.

    1986-01-01

    Establishment of a stable, transformed human renal carcinoma cell line that produces erythropoietin in vitro and has maintained this function continuously since 1981 and for > 150 passages in monolayer culture was accomplished by transplantation of human renal clear cell carcinoma tissue from a patient with erythrocytosis into an immunosuppressed athymic mouse. In addition to its immunocrossreactivity with native human urinary erythropoietin, the tumor erythropoietin demonstrates biological activity in the in vitro mouse erythroid colony-forming unit assay and in tumor-bearing nude mice. The cloned renal carcinoma cell line has an abnormal human karyotype and has ultrastructural features characteristic of human renal clear cell carcinoma. This cell line provides a reproducible model system for the production of an erythropoietin-like material and for the study of its synthesis and secretion.

  3. Derivation of human embryonic stem cell line Genea019

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    Biljana Dumevska

    2016-03-01

    Full Text Available The Genea019 human embryonic stem cell line was derived from a donated, fully commercially consented ART blastocyst, through ICM outgrowth on inactivated feeders. The line showed pluripotent cell morphology and genomic analysis verified a 46, XX karyotype, female Allele pattern and unaffected Htt CAG repeat length, compared to HD affected sibling Genea020. Pluripotency of Genea019 was demonstrated with 75% of cells expressing Nanog, 89% Oct4, 48% Tra1-60 and 85% SSEA4, a Pluritest Pluripotency score of 22.97, Novelty score of 1.42, tri-lineage teratoma formation and Alkaline Phosphatase activity. The cell line was negative for Mycoplasma and any visible contamination.

  4. Guidelines for the use of cell lines in biomedical research.

    Science.gov (United States)

    Geraghty, R J; Capes-Davis, A; Davis, J M; Downward, J; Freshney, R I; Knezevic, I; Lovell-Badge, R; Masters, J R W; Meredith, J; Stacey, G N; Thraves, P; Vias, M

    2014-09-09

    Cell-line misidentification and contamination with microorganisms, such as mycoplasma, together with instability, both genetic and phenotypic, are among the problems that continue to affect cell culture. Many of these problems are avoidable with the necessary foresight, and these Guidelines have been prepared to provide those new to the field and others engaged in teaching and instruction with the information necessary to increase their awareness of the problems and to enable them to deal with them effectively. The Guidelines cover areas such as development, acquisition, authentication, cryopreservation, transfer of cell lines between laboratories, microbial contamination, characterisation, instability and misidentification. Advice is also given on complying with current legal and ethical requirements when deriving cell lines from human and animal tissues, the selection and maintenance of equipment and how to deal with problems that may arise.

  5. Murine leukemia virus-derived retroviral vector has differential integration patterns in human cell lines used to produce recombinant factor VIII

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Correa de Freitas

    2014-06-01

    Full Text Available OBJECTIVE: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO and baby hamster kidney cells (BHK. Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.METHODS: This study used ligation-mediated polymerase chain reaction to locate the site of viral vector integration by sequencing polymerase chain reaction products. The sequences were compared to genomic databases to characterize respective clones.RESULTS: The retroviral vector presented different and non-random profiles of integration between cells lines. A preference of integration for chromosomes 19, 17 and 11 was observed for HepG2FVIIIdB/P140K and chromosome 9 for Hek293FVIIIdB/P140K. In genomic regions such as CpG islands and transcription factor binding sites, there was no difference in the integration profiles for both cell lines. Integration in intronic regions of encoding protein genes (RefSeq genes was also observed in both cell lines. Twenty percent of integrations occurred at fragile sites in the genome of the HepG2 cell line and 17% in Hek293.CONCLUSION: The results suggest that the cell type can affect the profile of chromosomal integration of the retroviral vector used; these differences may interfere in the level of expression of recombinant proteins.

  6. Differential Proteomics in Malignant and Normal Liver Cell Lines

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi-jun; WANG Bin; YAN Zhi-yong; QIAN Dong-meng; SONG Xu-xia; Ding Shou-yi; BAI Zhi-qiang

    2007-01-01

    Objective: To detect differential protein expression in malignant and normal liver cell lines in vitro using the SELDI ProteinChip platform, for investigating the pathogenesis of liver cancer. Methods: Two cell lines, human normal liver cell line L02 and hepatoma cell line SMMC-7721 were cultured routinely, harvested in good condition and lysed. After quantification, the supernatant of the lysate was tested by IMAC3 (Immobilized Mental Affinity Capture) and WCX2 (Weak Cation Exchange) chips on the SELDI-TOF-MS ProteinChip reader. Results: Protein expression differed between the malignant and normal liver cell lines. A total of 20 differentially expressed proteins were found, among which, 7 were captured by the IMAC3 chip and 14 by the WCX2 chip. Peaks at 5,419, 7,979 and 11,265 Da were higher and at 8,103, 8,492, 10,160 and 11,304 Da lower in SMMC-7721 cells by the IMAC3 chip; peaks at 7,517, 7,945 and 7,979 Da were higher and at 5,061, 5,551, 5,818, 7,439, 9,401,10,100, 10,312, 11,621, 11,662, 11,830 and 12,772 Da lower in SMMC-7721 cells by the WCX2 chip. Interestingly, both chips captured the 7,979 Da peak. In addition, the 11,081 Da peak corresponded precisely with the molecular mass of the calcium binding protein S100A10, which may participate in the formation of liver cancer in association with p36. Conclusion: Detecting differential protein expression in malignant and normal liver cell lines using the SELDI ProteinChip platform was simple, sensitive and repeatable. The results we obtained can serve as a basis for investigating the pathogenesis of liver cancer and aid the discovery of new therapeutic targets.

  7. Reconstruction of endometrium from human endometrial side population cell lines.

    Directory of Open Access Journals (Sweden)

    Irene Cervelló

    Full Text Available Endometrial regeneration is mediated, at least in part, by the existence of a specialized somatic stem cell (SSC population recently identified by several groups using the side population (SP technique. We previously demonstrated that endometrial SP displays genotypic, phenotypic and the functional capability to develop human endometrium after subcutaneous injection in NOD-SCID mice. We have now established seven human endometrial SP (hESP cell lines (ICE 1-7: four from the epithelial and three from the stromal fraction, respectively. SP cell lines were generated under hypoxic conditions based on their cloning efficiency ability, cultured for 12-15 passages (20 weeks and cryopreserved. Cell lines displayed normal 46XX karyotype, intermediate telomerase activity pattern and expressed mRNAs encoding proteins that are considered characteristic of undifferentiated cells (Oct-4, GDF3, DNMT3B, Nanog, GABR3 and those of mesodermal origin (WT1, Cardiac Actin, Enolase, Globin, REN. Phenotype analysis corroborated their epithelial (CD9+ or stromal (vimentin+ cell origin and mesenchymal (CD90+, CD73+ and CD45⁻ attributes. Markers considered characteristic of ectoderm or endoderm were not detected. Cells did not express either estrogen receptor alpha (ERα or progesterone receptor (PR. The hESP cell lines were able to differentiate in vitro into adipocytes and osteocytes, which confirmed their mesenchymal origin. Finally, we demonstrated their ability to generate human endometrium when transplanted beneath the renal capsule of NOD-SCID mice. These findings confirm that SP cells exhibit key features of human endometrial SSC and open up new possibilities for the understanding of gynecological disorders such as endometriosis or Asherman syndrome. Our cell lines can be a valuable model to investigate new targets for endometrium proliferation in endometriosis.

  8. Establishment, immortalisation and characterisation of pteropid bat cell lines.

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    Gary Crameri

    Full Text Available BACKGROUND: Bats are the suspected natural reservoir hosts for a number of new and emerging zoonotic viruses including Nipah virus, Hendra virus, severe acute respiratory syndrome coronavirus and Ebola virus. Since the discovery of SARS-like coronaviruses in Chinese horseshoe bats, attempts to isolate a SL-CoV from bats have failed and attempts to isolate other bat-borne viruses in various mammalian cell lines have been similarly unsuccessful. New stable bat cell lines are needed to help with these investigations and as tools to assist in the study of bat immunology and virus-host interactions. METHODOLOGY/FINDINGS: Black flying foxes (Pteropus alecto were captured from the wild and transported live to the laboratory for primary cell culture preparation using a variety of different methods and culture media. Primary cells were successfully cultured from 20 different organs. Cell immortalisation can occur spontaneously, however we used a retroviral system to immortalise cells via the transfer and stable production of the Simian virus 40 Large T antigen and the human telomerase reverse transcriptase protein. Initial infection experiments with both cloned and uncloned cell lines using Hendra and Nipah viruses demonstrated varying degrees of infection efficiency between the different cell lines, although it was possible to infect cells in all tissue types. CONCLUSIONS/SIGNIFICANCE: The approaches developed and optimised in this study should be applicable to bats of other species. We are in the process of generating further cell lines from a number of different bat species using the methodology established in this study.

  9. Monoclonal antibodies against the human leukemia cell line K 562.

    Science.gov (United States)

    Böttger, V; Hering, S; Jantscheff, P; Micheel, B

    1985-01-01

    Three monoclonal antibodies raised against K 562, a cell line originally established from a patient with chronic myeloid leukemia (CML) in terminal blast crisis, were selected according to their distinct reaction pattern. Whereas two antibodies (ZIK-C1-A/C5 and ZIK-C1-A/H5 also designated C and H) recognized antigens, present on K 562 cells and other immature and mature hematopoietic cells (cell lines and normal blood and bone marrow cells), antibody ZIK-C1-A/D9 also designated Y showed an exclusive binding to K 562 cells. The results obtained (here and in the following paper) indicate, that antibody ZIK-C1-A/D9 defines an early differentiation antigen of hematopoiesis or a leukemia-associated antigen.

  10. Comparative Metabolic Flux Profiling of Melanoma Cell Lines

    Science.gov (United States)

    Scott, David A.; Richardson, Adam D.; Filipp, Fabian V.; Knutzen, Christine A.; Chiang, Gary G.; Ronai, Ze'ev A.; Osterman, Andrei L.; Smith, Jeffrey W.

    2011-01-01

    Metabolic rewiring is an established hallmark of cancer, but the details of this rewiring at a systems level are not well characterized. Here we acquire this insight in a melanoma cell line panel by tracking metabolic flux using isotopically labeled nutrients. Metabolic profiling and flux balance analysis were used to compare normal melanocytes to melanoma cell lines in both normoxic and hypoxic conditions. All melanoma cells exhibited the Warburg phenomenon; they used more glucose and produced more lactate than melanocytes. Other changes were observed in melanoma cells that are not described by the Warburg phenomenon. Hypoxic conditions increased fermentation of glucose to lactate in both melanocytes and melanoma cells (the Pasteur effect). However, metabolism was not strictly glycolytic, as the tricarboxylic acid (TCA) cycle was functional in all melanoma lines, even under hypoxia. Furthermore, glutamine was also a key nutrient providing a substantial anaplerotic contribution to the TCA cycle. In the WM35 melanoma line glutamine was metabolized in the “reverse” (reductive) direction in the TCA cycle, particularly under hypoxia. This reverse flux allowed the melanoma cells to synthesize fatty acids from glutamine while glucose was primarily converted to lactate. Altogether, this study, which is the first comprehensive comparative analysis of metabolism in melanoma cells, provides a foundation for targeting metabolism for therapeutic benefit in melanoma. PMID:21998308

  11. Cell death in mammalian cell culture: molecular mechanisms and cell line engineering strategies

    OpenAIRE

    Krampe, Britta; Al-Rubeai, Mohamed

    2010-01-01

    Cell death is a fundamentally important problem in cell lines used by the biopharmaceutical industry. Environmental stress, which can result from nutrient depletion, by-product accumulation and chemical agents, activates through signalling cascades regulators that promote death. The best known key regulators of death process are the Bcl-2 family proteins which constitute a critical intracellular checkpoint of apoptosis cell death within a common death pathway. Engineering of several members o...

  12. Skin Biopsy and Patient-Specific Stem Cell Lines

    Science.gov (United States)

    Li, Yao; Nguyen, Huy V.; Tsang, Stephen H.

    2016-01-01

    The generation of patient-specific induced pluripotent stem (iPS) cells permits the development of next-generation patient-specific systems biology models reflecting personalized genomics profiles to better understand pathophysiology. In this chapter, we describe how to create a patient-specific iPS cell line. There are three major steps: (1) performing a skin biopsy procedure on the patient; (2) extracting human fibroblast cells from the skin biopsy tissue; and (3) reprogramming patient-specific fibroblast cells into the pluripotent stem cell stage. PMID:26141312

  13. The YUMM lines: a series of congenic mouse melanoma cell lines with defined genetic alterations.

    Science.gov (United States)

    Meeth, Katrina; Wang, Jake Xiao; Micevic, Goran; Damsky, William; Bosenberg, Marcus W

    2016-09-01

    The remarkable success of immune therapies emphasizes the need for immune-competent cancer models. Elegant genetically engineered mouse models of a variety of cancers have been established, but their effective use is limited by cost and difficulties in rapidly generating experimental data. Some mouse cancer cell lines are transplantable to immunocompetent host mice and have been utilized extensively to study cancer immunology. Here, we describe the Yale University Mouse Melanoma (YUMM) lines, a comprehensive system of mouse melanoma cell lines that are syngeneic to C57BL/6, have well-defined human-relevant driver mutations, and are genomically stable. This will be a useful tool for the study of tumor immunology and genotype-specific cancer biology.

  14. A functional analysis of N-glycosylation-related genes on sialylation of recombinant erythropoietin in six commonly used mammalian cell lines.

    Science.gov (United States)

    Zhang, Peiqing; Tan, Diana Lifen; Heng, Desmond; Wang, Tianhua; Mariati; Yang, Yuansheng; Song, Zhiwei

    2010-11-01

    Significant efforts have been made to improve the sialylation of recombinant glycoproteins with the aim of extending their in vivo circulation time. Here, we report a systematic functional analysis of 31 N-glycosylation-related genes on sialylation of recombinant EPO in six cell lines. BHK and CHO cells were found to sialylate recombinant EPO most effectively. None of the 31 genes, individually or in combination, was able to improve EPO sialylation in these cells. HEK293, Cos-7 and 3T3 cells showed intermediate sialylation capabilities, whereas NS0 cells sialylated recombinant EPO poorly. Overexpression of ST6GalI, ST3GalIII or ST3GalIV, but not ST3GalVI, was able to improve EPO sialylation in these four cell lines. qRT-PCR experiments revealed that ST3GalIII and ST3GalIV are indeed under expressed in HEK293, 3T3 and NS0 cells. Co-expression of upstream glycogenes failed to synergize with these sialyltransferases to further enhance sialylation, suggesting that the upstream glycogenes are all expressed at sufficient levels.

  15. Human cell lines: A promising alternative for recombinant FIX production.

    Science.gov (United States)

    de Sousa Bomfim, Aline; Cristina Corrêa de Freitas, Marcela; Picanço-Castro, Virgínia; de Abreu Soares Neto, Mário; Swiech, Kamilla; Tadeu Covas, Dimas; Maria de Sousa Russo, Elisa

    2016-05-01

    Factor IX (FIX) is a vitamin K-dependent protein, and it has become a valuable pharmaceutical in the Hemophilia B treatment. We evaluated the potential of recombinant human FIX (rhFIX) expression in 293T and SK-Hep-1 human cell lines. SK-Hep-1-FIX cells produced higher levels of biologically active protein. The growth profile of 293T-FIX cells was not influenced by lentiviral integration number into the cellular genome. SK-Hep-1-FIX cells showed a significantly lower growth rate than SK-Hep-1 cells. γ-carboxylation process is significant to FIX biological activity, thus we performed a expression analysis of genes involved in this process. The 293T gene expression suggests that this cell line could efficiently carboxylate FIX, however only 28% of the total secreted protein is active. SK-Hep-1 cells did not express high amounts of VKORC1 and carboxylase, but this cell line secreted large amounts of active protein. Enrichment of culture medium with Ca(+2) and Mg(+2) ions did not affect positively rhFIX expression in SK-Hep-1 cells. In 293T cells, the addition of 0.5 mM Ca(+2) and 1 mM Mg(+2) resulted in higher rhFIX concentration. SK-Hep-1 cell line proved to be very effective in rhFIX production, and it can be used as a novel biotechnological platform for the production of recombinant proteins.

  16. Casein gene expression in mouse mammary epithelial cell lines: Dependence upon extracellular matrix and cell type

    Energy Technology Data Exchange (ETDEWEB)

    Medina, D.; Oborn, C.J. (Baylor College of Medicine, Houston, TX (USA)); Li, M.L.; Bissell, M.J. (Univ. of California, Berkeley (USA))

    1987-09-01

    The COMMA-D mammary cell line exhibits mammary-specific functional differentiation under appropriate conditions in cell culture. The cytologically heterogeneous COMMA-D parental line and the clonal lines DB-1, TA-5, and FA-1 derived from the COMMA-D parent were examined for similar properties of functional differentiation. In monolayer cell culture, the cell lines DB-1, TA-5, FA-1, and MA-4 were examined for expression of mammary-specific and epithelial-specific proteins by an indirect immunofluorescence assay. The clonal cell lines were relatively homogeneous in their respective staining properties and seemed to represent three subpopulations found in the heterogeneous parental COMMA-D lines. None of the four clonal lines appeared to represent myoepithelial cells. The cell lines were examined for expression of {beta}-casein mRNA in the presence or absence of prolactin. The inducibility of {beta}-casein in the COMMA-D cell line was further enhanced by a reconstituted basement membrane preparation enriched in laminin, collagen IV, and proteoglycans. These results support the hypothesis that the functional response of inducible mammary cell populations is a result of interaction among hormones, multiple extracellular matrix components, and specific cell types.

  17. Analysis of LINE-1 expression in human pluripotent cells.

    Science.gov (United States)

    Muñoz-Lopez, Martin; Garcia-Cañadas, Marta; Macia, Angela; Morell, Santiago; Garcia-Perez, Jose L

    2012-01-01

    Half of the human genome is composed of repeated DNA, and some types are mobile within our genome (transposons and retrotransposons). Despite their abundance, only a small fraction of them are currently active in our genome (Long Interspersed Element-1 (LINE-1), Alu, and SVA elements). LINE-1 or L1 elements are a family of active non-LTR retrotransposons, the ongoing mobilization of which still impacts our genome. As selfish DNA elements, L1 activity is more prominent in early human development, where new insertions would be transmitted to the progeny. Here, we describe the conventional methods aimed to determine the expression level of LINE-1 elements in pluripotent human cells.

  18. Establishment of cell suspension line of Populus tomentosa Carr

    Institute of Scientific and Technical Information of China (English)

    YAO Na; ZHANG Zhi-yi; AN Xin-min; YANG Kai

    2008-01-01

    Leaves of fine Populus tomentosa genotype TC152 were used as explants to establish cell suspension lines. The effects of plant growth regulators on callus induction and establishment of cell suspension lines were studied. The callus induction rate was the highest on a MS solid medium supplemented with 1.0 mg·L-1 2,4-D. A cell suspension line could be obtained by inoculating calli which were not subeultured into a MS liquid medium supplemented with 1.5 mg·L-1 2,4-D. The best subculture medium was MS+ 0.8 mg·L-1 2,4-D + 30 g·L-1 sucrose with a subculture cycle of seven days.

  19. Graphene Oxide Nanoribbons Induce Autophagic Vacuoles in Neuroblastoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Emanuela Mari

    2016-11-01

    Full Text Available Since graphene nanoparticles are attracting increasing interest in relation to medical applications, it is important to understand their potential effects on humans. In the present study, we prepared graphene oxide (GO nanoribbons by oxidative unzipping of single-wall carbon nanotubes (SWCNTs and analyzed their toxicity in two human neuroblastoma cell lines. Neuroblastoma is the most common solid neoplasia in children. The hallmark of these tumors is the high number of different clinical variables, ranging from highly metastatic, rapid progression and resistance to therapy to spontaneous regression or change into benign ganglioneuromas. Patients with neuroblastoma are grouped into different risk groups that are characterized by different prognosis and different clinical behavior. Relapse and mortality in high risk patients is very high in spite of new advances in chemotherapy. Cell lines, obtained from neuroblastomas have different genotypic and phenotypic features. The cell lines SK-N-BE(2 and SH-SY5Y have different genetic mutations and tumorigenicity. Cells were exposed to low doses of GO for different times in order to investigate whether GO was a good vehicle for biological molecules delivering individualized therapy. Cytotoxicity in both cell lines was studied by measuring cellular oxidative stress (ROS, mitochondria membrane potential, expression of lysosomial proteins and cell growth. GO uptake and cytoplasmic distribution of particles were studied by Transmission Electron Microscopy (TEM for up to 72 h. The results show that GO at low concentrations increased ROS production and induced autophagy in both neuroblastoma cell lines within a few hours of exposure, events that, however, are not followed by growth arrest or death. For this reason, we suggest that the GO nanoparticle can be used for therapeutic delivery to the brain tissue with minimal effects on healthy cells.

  20. Dipeptidyl peptidase IV in two human glioma cell lines

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    A Sedo

    2009-12-01

    Full Text Available There is growing evidence that dipeptidyl peptidase IV [DPP-IV, EC 3.4.14.5] takes part in the metabolism of biologically active peptides participating in the regulation of growth and transformation of glial cells. However, the knowledge on the DPP-IV expression in human glial and glioma cells is still very limited. In this study, using histochemical and biochemical techniques, the DPP-IV activity was demonstrated in two commercially available human glioma cell lines of different transformation degree, as represented by U373 astrocytoma (Grade III and U87 glioblastoma multiforme (Grade IV lines. Higher total activity of the enzyme, as well as its preferential localisation in the plasma membrane, was observed in U87 cells. Compared to U373 population, U87 cells were morphologically more pleiomorphic, they were cycling at lower rate and expressing less Glial Fibrillary Acidic Protein. The data revealed positive correlation between the degree of transformation of cells and activity of DPP-IV. Great difference in expression of this enzyme, together with the phenotypic differences of cells, makes these lines a suitable standard model for further 57 studies of function of this enzyme in human glioma cells.

  1. Oral bioavailability of glyphosate: studies using two intestinal cell lines.

    Science.gov (United States)

    Vasiluk, Luba; Pinto, Linda J; Moore, Margo M

    2005-01-01

    Glyphosate is a commonly used nonselective herbicide that inhibits plant growth through interference with the production of essential aromatic amino acids. In vivo studies in mammals with radiolabeled glyphosate have shown that 34% of radioactivity was associated with intestinal tissue 2 h after oral administration. The aim of our research was to investigate the transport, binding, and toxicity of glyphosate to the cultured human intestinal epithelial cell line, Caco-2, and the rat small intestinal crypt-derived cell line, ileum epithelial cells-18 (IEC-18). An in vitro analysis of the transport kinetics of [14C]-glyphosate showed that 4 h after exposure, approximately 8% of radiolabeled glyphosate moved through the Caco-2 monolayer in a dose-dependent manner. Binding of glyphosate to cells was saturable and approximately 4 x 10(11) binding sites/cell were estimated from bound [14C]. Exposure of Caco-2 cells to > or =10 mg/ml glyphosate reduced transmembrane electrical resistance (TEER) by 82 to 96% and increased permeability to [3H]-mannitol, indicating that paracellular permeability increased in glyphosate-treated cells. At 10-mg/ml glyphosate, both IEC-18 and Caco-2 cells showed disruption in the actin cytoskeleton. In Caco-2 cells, significant lactate dehydrogenase leakage was observed when cells were exposed to 15 mg/ml of glyphosate. These data indicate that at doses >10 mg/ml, glyphosate significantly disrupts the barrier properties of cultured intestinal cells.

  2. Derivation of a Homozygous Human Androgenetic Embryonic Stem Cell Line.

    Science.gov (United States)

    Ding, Chenhui; Huang, Sunxing; Qi, Quan; Fu, Rui; Zhu, Wanwan; Cai, Bing; Hong, Pingping; Liu, Zhengxin; Gu, Tiantian; Zeng, Yanhong; Wang, Jing; Xu, Yanwen; Zhao, Xiaoyang; Zhou, Qi; Zhou, Canquan

    2015-10-01

    Human embryonic stem cells (hESCs) have long been considered as a promising source for cell replacement therapy. However, one major obstacle for the use of these cells is immune compatibility. Histocompatible human parthenogenetic ESCs have been reported as a new method for generating human leukocyte antigen (HLA)-matched hESCs. To further investigate the possibility of obtaining histocompatible stem cells from uniparental embryos, we tried to produce androgenetic haploid human embryos by injecting a single spermatozoon into enucleated human oocyte, and establish human androgenetic embryonic stem (hAGES) cell lines from androgenetic embryos. In the present study, a diploid hAGES cell line has been established, which exhibits typical features of human ESCs, including the expression of pluripotency markers, having differentiation potential in vitro and in vivo, and stable propagation in an undifferentiated state (>P40). Bisulfite sequencing of the H19, Snrpn, Meg3, and Kv imprinting control regions suggested that hAGES cells maintained to a certain extent a sperm methylation pattern. Genome-wide single nucleotide polymorphism, short tandem repeat, and HLA analyses revealed that the hAGES cell genome was highly homozygous. These results suggest that hAGES cells from spermatozoon could serve as a useful tool for studying the mechanisms underlying genomic imprinting in humans. It might also be used as a potential resource for cell replacement therapy as parthenogenetic stem cells.

  3. Antiproliferative effect of Tualang honey on oral squamous cell carcinoma and osteosarcoma cell lines

    Directory of Open Access Journals (Sweden)

    Ismail Noorliza M

    2010-09-01

    Full Text Available Abstract Background The treatment of oral squamous cell carcinomas (OSCC and human osteosarcoma (HOS includes surgery and/or radiotherapy which often lead to reduced quality of life. This study was aimed to study the antiproliferative activity of local honey (Tualang on OSCC and HOS cell lines. Methods Several concentrations of Tualang honey (1% - 20% were applied on OSCC and HOS cell lines for 3, 6, 12, 24, 48 and 72 hours. Morphological characteristics were observed under light and fluorescent microscope. Cell viability was assessed using MTT assay and the optical density for absorbance values in each experiment was measured at 570 nm by an ELISA reader. Detection of cellular apoptosis was done using the Annexin V-FITC Apoptosis Detection Kit. Results Morphological appearance showed apoptotic cellular changes like becoming rounded, reduction in cell number, blebbed membrane and apoptotic nuclear changes like nuclear shrinkage, chromatin condensation and fragmented nucleus on OSCC and HOS cell lines. Cell viability assay showed a time and dose-dependent inhibitory effect of honey on both cell lines. The 50% inhibitory concentration (IC50 for OSCC and HOS cell lines was found to be 4% and 3.5% respectively. The maximum inhibition of cell growth of ≥80% was obtained at 15% for both cell lines. Early apoptosis was evident by flow cytometry where percentage of early apoptotic cells increased in dose and time dependent manner. Conclusion Tualang honey showed antiproliferative effect on OSCC and HOS cell lines by inducing early apoptosis.

  4. Identification and Characterization of Cancer Stem Cells from Head and Neck Squamous Cell Carcinoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Valentina Pozzi

    2015-05-01

    Full Text Available Background/Aims: Head and neck squamous cell carcinoma (HNSCC ranks sixth worldwide for tumor-related mortality. A subpopulation of tumor cells, termed cancer stem cells (CSCs, has the ability to support cancer growth. Therefore, profiling CSC-enriched populations could be a reliable tool to study cancer biology. Methods: We performed phenotypic characterization of 7 HNSCC cell lines and evaluated the presence of CSCs. CSCs from Hep-2 cell line and HNSCC primary cultures were enriched through sphere formation and sphere-forming cells have been characterized both in vitro and in vivo. In addition, we investigated the expression levels of Nicotinamide N-methyltransferase (NNMT, an enzyme overexpressed in several malignancies. Results: CSC markers were markedly expressed in Hep-2 cell line, which was found to be highly tumorigenic. CSC-enriched populations displayed increased expression of CSC markers and a strong capability to form tumors in vivo. We also found an overexpression of CSC markers in tumor formed by CSC-enriched populations. Interestingly, NNMT levels were significantly higher in CSC-enriched populations compared with parental cells. Conclusion: Our study provides an useful procedure for CSC identification and enrichment in HNSCC. Moreover, results obtained seem to suggest that CSCs may represent a promising target for an anticancer therapy.

  5. Boldine: a potential new antiproliferative drug against glioma cell lines.

    Science.gov (United States)

    Gerhardt, Daniéli; Horn, Ana Paula; Gaelzer, Mariana Maier; Frozza, Rudimar Luiz; Delgado-Cañedo, Andrés; Pelegrini, Alessandra Luiza; Henriques, Amélia T; Lenz, Guido; Salbego, Christianne

    2009-12-01

    Malignant gliomas are the most common and devastating primary tumors of the central nervous system. Currently no efficient treatment is available. This study evaluated the effect and underlying mechanisms of boldine, an aporphine alkaloid of Peumus boldus, on glioma proliferation and cell death. Boldine decreased the cell number of U138-MG, U87-MG and C6 glioma lines at concentrations of 80, 250 and 500 muM. We observed that cell death caused by boldine was cell-type specific and dose-dependent. Exposure to boldine for 24 h did not activate key mediators of apoptosis. However, it induced alterations in the cell cycle suggesting a G(2)/M arrest in U138-MG cells. Boldine had no toxic effect on non-tumor cells when used at the same concentrations as those used on tumor cells. Based on these results, we speculate that boldine may be a promising compound for evaluation as an anti-cancer agent.

  6. Characterization of cloned cells from an immortalized fetal pulmonary type II cell line

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R.F.; Waide, J.J.; Lechner, J.F.

    1995-12-01

    A cultured cell line that maintained expression of pulmonary type II cell markers of differentiation would be advantageous to generate a large number of homogenous cells in which to study the biochemical functions of type II cells. Type II epithelial cells are the source of pulmonary surfactant and a cell of origin for pulmonary adenomas. Last year our laboratory reported the induction of expression of two phenotypic markers of pulmonary type II cells (alkaline phosphatase activity and surfactant lipid synthesis) in cultured fetal rat lung epithelial (FRLE) cells, a spontaneously immortalized cell line of fetal rat lung type II cell origin. Subsequently, the induction of the ability to synthesize surfactant lipid became difficult to repeat. We hypothesized that the cell line was heterogenuous and some cells were more like type II cells than others. The purpose of this study was to test this hypothesis and to obtain a cultured cell line with type II cell phenotypic markers by cloning several FRLE cells and characterizing them for phenotypic markers of type II cells (alkaline phosphatase activity and presence of surfactant lipids). Thirty cloned cell lines were analyzed for induced alkaline phosphatase activity (on x-axis) and for percent of phospholipids that were disaturated (i.e., surfactant).

  7. LINEing germ and embryonic stem cells' silencing of retrotransposons.

    Science.gov (United States)

    Ishiuchi, Takashi; Torres-Padilla, Maria-Elena

    2014-07-01

    Almost half of our genome is occupied by transposable elements. Although most of them are inactive, one type of non-long terminal repeat (LTR) retrotransposon, long interspersed nuclear element 1 (LINE1), is capable of retrotransposition. Two studies in this issue, Pezic and colleagues (pp. 1410-1428) and Castro-Diaz and colleagues (pp. 1397-1409), provide novel insight into the regulation of LINE1s in human embryonic stem cells and mouse germ cells and shed new light on the conservation of complex mechanisms to ensure silencing of transposable elements in mammals.

  8. Cell death in mammalian cell culture: molecular mechanisms and cell line engineering strategies.

    Science.gov (United States)

    Krampe, Britta; Al-Rubeai, Mohamed

    2010-07-01

    Cell death is a fundamentally important problem in cell lines used by the biopharmaceutical industry. Environmental stress, which can result from nutrient depletion, by-product accumulation and chemical agents, activates through signalling cascades regulators that promote death. The best known key regulators of death process are the Bcl-2 family proteins which constitute a critical intracellular checkpoint of apoptosis cell death within a common death pathway. Engineering of several members of the anti-apoptosis Bcl-2 family genes in several cell types has extended the knowledge of their molecular function and interaction with other proteins, and their regulation of cell death. In this review, we describe the various modes of cell death and their death pathways at molecular and organelle level and discuss the relevance of the growing knowledge of anti-apoptotic engineering strategies to inhibit cell death and increase productivity in mammalian cell culture.

  9. The Long Intron 1 of Growth Hormone Gene from Reeves’ Turtle (Chinemys reevesii Correlates with Negatively Regulated GH Expression in Four Cell Lines

    Directory of Open Access Journals (Sweden)

    Wen-Sheng Liu

    2016-04-01

    Full Text Available Turtles grow slowly and have a long lifespan. Ultrastructural studies of the pituitary gland in Reeves’ turtle (Chinemys reevesii have revealed that the species possesses a higher nucleoplasmic ratio and fewer secretory granules in growth hormone (GH cells than other animal species in summer and winter. C. reevesii GH gene was cloned and species-specific similarities and differences were investigated. The full GH gene sequence in C. reevesii contains 8517 base pairs (bp, comprising five exons and four introns. Intron 1 was found to be much longer in C. reevesii than in other species. The coding sequence (CDS of the turtle’s GH gene, with and without the inclusion of intron 1, was transfected into four cell lines, including DF-1 chicken embryo fibroblasts, Chinese hamster ovary (CHO cells, human embryonic kidney 293FT cells, and GH4C1 rat pituitary cells; the turtle growth hormone (tGH gene mRNA and protein expression levels decreased significantly in the intron-containing CDS in these cell lines, compared with that of the corresponding intronless CDS. Thus, the long intron 1 of GH gene in Reeves’ turtle might correlate with downregulated gene expression.

  10. The Long Intron 1 of Growth Hormone Gene from Reeves' Turtle (Chinemys reevesii) Correlates with Negatively Regulated GH Expression in Four Cell Lines.

    Science.gov (United States)

    Liu, Wen-Sheng; Ma, Jing-E; Li, Wei-Xia; Zhang, Jin-Ge; Wang, Juan; Nie, Qing-Hua; Qiu, Feng-Fang; Fang, Mei-Xia; Zeng, Fang; Wang, Xing; Lin, Xi-Ran; Zhang, Li; Chen, Shao-Hao; Zhang, Xi-Quan

    2016-04-12

    Turtles grow slowly and have a long lifespan. Ultrastructural studies of the pituitary gland in Reeves' turtle (Chinemys reevesii) have revealed that the species possesses a higher nucleoplasmic ratio and fewer secretory granules in growth hormone (GH) cells than other animal species in summer and winter. C. reevesii GH gene was cloned and species-specific similarities and differences were investigated. The full GH gene sequence in C. reevesii contains 8517 base pairs (bp), comprising five exons and four introns. Intron 1 was found to be much longer in C. reevesii than in other species. The coding sequence (CDS) of the turtle's GH gene, with and without the inclusion of intron 1, was transfected into four cell lines, including DF-1 chicken embryo fibroblasts, Chinese hamster ovary (CHO) cells, human embryonic kidney 293FT cells, and GH4C1 rat pituitary cells; the turtle growth hormone (tGH) gene mRNA and protein expression levels decreased significantly in the intron-containing CDS in these cell lines, compared with that of the corresponding intronless CDS. Thus, the long intron 1 of GH gene in Reeves' turtle might correlate with downregulated gene expression.

  11. Dipalmitoyl-phosphatidylcholine biosynthesis is induced by non-injurious mechanical stretch in a model of alveolar type II cells.

    Science.gov (United States)

    Pantazi, Despoina; Kitsiouli, Eirini; Karkabounas, Athanasios; Trangas, Theoni; Nakos, George; Lekka, Marilena E

    2013-08-01

    Dipalmitoylphosphatidylcholine, (DP-PtdCho), the major phospholipid component of lung surfactant is biosynthesized via a de novo pathway, the last step of which is catalyzed by CDP-choline:cholinephosphotransferase (CPT) and two remodeling steps: a deacylation and a reacylation one, catalyzed by an acidic, Ca²⁺-independent phospholipase A₂ (aiPLA₂) and a lyso-phosphatidylcholine acyltransferase (LPCAT), respectively. The aim of our study was to investigate whether a low magnitude, non-injurious static mode of mechanical stretch can induce phosphatidylcholine (PtdCho) biosynthesis and its remodeling to DP-PtdCho in the A549 cell-line, a model of alveolar type II cells. The deformation of A549 cells did not cause any release of lactate dehydrogenase, or phospholipids into the cell culture supernatants. An increase in PtdCho levels was observed after 1 h of static stretching, especially among the DP-PtdCho molecular species, as indicated by targeted lipidomics approach and site-directed fatty acyl-chain analysis. Moreover, although sphingomyelin (CerPCho) levels were unaffected, the DP-PtdCho/CerPCho ratio increased. Induction was observed in CPT, LPCAT and aiPLA₂ enzymatic activities and gene expression. Finally, incubation of the cells with MJ33 suppressed aiPLA₂ activity and DP-PtdCho production. Our data suggest that mild static mechanical stretch can promote the biosynthesis of PtdCho and its remodeling to DP-PtdCho in lung epithelial cells. Thus, low magnitude stretch could contribute to protective mechanisms rather than to injurious ones.

  12. Cellular and Phenotypic Characterization of Canine Osteosarcoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Marie E. Legare, Jamie Bush, Amanda K. Ashley, Taka Kato, William H. Hanneman

    2011-01-01

    Full Text Available Canine and human osteosarcoma (OSA have many similarities, with the majority of reported cases occurring in the appendicular skeleton, gender predominance noted, high rate of metastasis at the time of presentation, and a lack of known etiology for this devastating disease. Due to poor understanding of the molecular mechanisms underlying OSA, we have characterized seven different OSA canine cell lines: Abrams, D17, Grey, Hughes, Ingles, Jarques, and Marisco and compared them to U2, a human OSA cell line, for the following parameters: morphology, growth, contact inhibition, migrational tendencies, alkaline phosphatase staining, heterologous tumor growth, double-strand DNA breaks, and oxidative damage. All results demonstrated the positive characteristics of the Abrams cell line for use in future studies of OSA. Of particular interest, the robust growth of a subcutaneous tumor and rapid pulmonary metastasis of the Abrams cell line in an immunocompromised mouse shows incredible potential for the future use of Abrams as a canine OSA model. Further investigations utilizing a canine cell model of OSA, such as Abrams, will be invaluable to understanding the molecular events underlying OSA, pharmaceutical inhibition of metastasis, and eventual prevention of this devastating disease.

  13. Osmotic stress affects functional properties of human melanoma cell lines

    CERN Document Server

    La Porta, Caterina A M; Pasini, Maria; Laurson, Lasse; Alava, Mikko J; Zapperi, Stefano; Amar, Martine Ben

    2015-01-01

    Understanding the role of microenvironment in cancer growth and metastasis is a key issue for cancer research. Here, we study the effect of osmotic pressure on the functional properties of primary and metastatic melanoma cell lines. In particular, we experimentally quantify individual cell motility and transmigration capability. We then perform a circular scratch assay to study how a cancer cell front invades an empty space. Our results show that primary melanoma cells are sensitive to a low osmotic pressure, while metastatic cells are less. To better understand the experimental results, we introduce and study a continuous model for the dynamics of a cell layer and a stochastic discrete model for cell proliferation and diffusion. The two models capture essential features of the experimental results and allow to make predictions for a wide range of experimentally measurable parameters.

  14. Optimized protocol for derivation of human embryonic stem cell lines.

    Science.gov (United States)

    Camarasa, María Vicenta; Galvez, Víctor Miguel; Brison, Daniel Roy; Bachiller, Daniel

    2012-09-01

    For the past 12 years, the biology and applications of human embryonic stem cells (hESCs) have received great attention from the scientific community. Derivatives of the first hESC line obtained by J. Thomson's group (Science 282(5391):1145-1147, 1998) have been used in clinical trials in patients with spinal cord injury, and other hESC lines have now been used to generate cells for use in treating blindness (Lancet 379(9817):713-720, 2012). In addition to the classical protocol based on mouse or human feeder layers using open culture methods (In Vitro Cellular & Developmental Biology - Animal 46(3-4):386-394, 2010; Stem Cells 23(9):1221-1227, 2005; Nature Biotechnology 24(2):185-187, 2006; Human Reproduction 21(2):503-511, 2006; Human Reproduction 20(8):2201-2206, 2005; Fertility and Sterility 83(5):1517-1529, 2005), novel hESC lines have been derived xeno-free (without using animal derived reagents) (PLoS One 5 (4):1024-1026, 2010), feeder-free (without supporting cell monolayers) (Lancet 365(9471):1601-1603, 2005), in microdrops under oil (In Vitro Cellular & Developmental Biology - Animal 46(3-4):236-41, 2010) and in suspension with ROCK inhibitor (Nature Biotechnology 28(4):361-4, 2010). Regardless of the culture system, successful hESC derivation usually requires optimization of embryo culture, the careful and timely isolation of its inner cell mass (ICM), and precise culture conditions up to the establishment of pluripotent cell growth during hESC line derivation. Herein we address the crucial steps of the hESC line derivation protocol, and provide tips to apply quality control to each step of the procedure.

  15. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yslas, Edith I., E-mail: eyslas@exa.unrc.edu.ar [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Cavallo, Pablo; Acevedo, Diego F.; Barbero, César A. [Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Rivarola, Viviana A. [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina)

    2015-06-01

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines.

  16. UOK 268 Cell Line for Hereditary Leiomyomatosis and Renal Cell Carcinoma | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute’s Urologic Oncology Branch seeks parties to co-develop the UOK 262 immortalized cell line as research tool to study aggressive hereditary leiomyomatosis and renal cell carcinoma (HLRCC)-associated recurring kidney cancer.

  17. Third-line chemotherapy for small cell lung cancer

    NARCIS (Netherlands)

    de Jong, WK; ten Hacken, NHT; Groen, HJM

    2006-01-01

    Efficacy of third-line chemotherapy treatment for small cell lung cancer (SCLC) is unknown. We present our experience with third-tine chemotherapy for recurrent SCLC. Between January 1996 and July 2004 all. consecutive patients treated for SCLC were retrospectively studied. We recorded patient chara

  18. UV light blocks EGFR signalling in human cancer cell lines

    DEFF Research Database (Denmark)

    Olsen, BB; Neves-Petersen, M T; Klitgaard, S

    2007-01-01

    UV light excites aromatic residues, causing these to disrupt nearby disulphide bridges. The EGF receptor is rich in aromatic residues near the disulphide bridges. Herein we show that laser-pulsed UV illumination of two different skin-derived cancer cell lines i.e. Cal-39 and A431, which both...

  19. Silicon Carbide Tiles for Sidewall Lining in Aluminium Electrolysis Cells

    Institute of Scientific and Technical Information of China (English)

    RUANBo; ZHAOJunguo; 等

    1999-01-01

    The paper introduces the nitride bonded silicon carbide used for sidewall lining in aluminium eletrolysis cells ,including technical process,main properties and application results.Comparison tests on various physical properties of silicon carbide products made by LIRR and other producers worldwide have also been conducted in an independent laboratory.

  20. 76 FR 16609 - Proposed Information Collection; Comment Request; Identification of Human Cell Lines Project

    Science.gov (United States)

    2011-03-24

    ...; Identification of Human Cell Lines Project AGENCY: National Institute of Standards and Technology (NIST...) profiling up to 1500 human cell line samples as part of the Identification of Human Cell Lines Project. All... for Biotechnology Information (NCBI) and will be used to differentiate among cell lines, as...

  1. Crude subcellular fractionation of cultured mammalian cell lines

    Directory of Open Access Journals (Sweden)

    Holden Paul

    2009-12-01

    Full Text Available Abstract Background The expression and study of recombinant proteins in mammalian culture systems can be complicated during the cell lysis procedure by contaminating proteins from cellular compartments distinct from those within which the protein of interest resides and also by solubility issues that may arise from the use of a single lysis buffer. Partial subcellular fractionation using buffers of increasing stringency, rather than whole cell lysis is one way in which to avoid or reduce this contamination and ensure complete recovery of the target protein. Currently published protocols involve time consuming centrifugation steps which may require expensive equipment and commercially available kits can be prohibitively expensive when handling large or multiple samples. Findings We have established a protocol to sequentially extract proteins from cultured mammalian cells in fractions enriched for cytosolic, membrane bound organellar, nuclear and insoluble proteins. All of the buffers used can be made inexpensively and easily and the protocol requires no costly equipment. While the method was optimized for a specific cell type, we demonstrate that the protocol can be applied to a variety of commonly used cell lines and anticipate that it can be applied to any cell line via simple optimization of the primary extraction step. Conclusion We describe a protocol for the crude subcellular fractionation of cultured mammalian cells that is both straightforward and cost effective and may facilitate the more accurate study of recombinant proteins and the generation of purer preparations of said proteins from cell extracts.

  2. Sphere-forming cell subpopulations with cancer stem cell properties in human hepatoma cell lines

    Directory of Open Access Journals (Sweden)

    Chen Lei

    2011-06-01

    Full Text Available Abstract Background Cancer stem cells (CSCs are regarded as the cause of tumor formation and recurrence. The isolation and identification of CSCs could help to develop novel therapeutic strategies specifically targeting CSCs. Methods Human hepatoma cell lines were plated in stem cell conditioned culture system allowed for sphere forming. To evaluate the stemness characteristics of spheres, the self-renewal, proliferation, chemoresistance, tumorigenicity of the PLC/PRF/5 sphere-forming cells, and the expression levels of stem cell related proteins in the PLC/PRF/5 sphere-forming cells were assessed, comparing with the parental cells. The stem cell RT-PCR array was performed to further explore the biological properties of liver CSCs. Results The PLC/PRF/5, MHCC97H and HepG2 cells could form clonal nonadherent 3-D spheres and be serially passaged. The PLC/PRF/5 sphere-forming cells possessed a key criteria that define CSCs: persistent self-renewal, extensive proliferation, drug resistance, overexpression of liver CSCs related proteins (Oct3/4, OV6, EpCAM, CD133 and CD44. Even 500 sphere-forming cells were able to form tumors in NOD/SCID mice, and the tumor initiating capability was not decreased when spheres were passaged. Besides, downstream proteins DTX1 and Ep300 of the CSL (CBF1 in humans, Suppressor of hairless in Drosophila and LAG1 in C. elegans -independent Notch signaling pathway were highly expressed in the spheres, and a gamma-secretase inhibitor MRK003 could significantly inhibit the sphere formation ability. Conclusions Nonadherent tumor spheres from hepatoma cell lines cultured in stem cell conditioned medium possess liver CSC properties, and the CSL-independent Notch signaling pathway may play a role in liver CSCs.

  3. THP-1 cell line: an in vitro cell model for immune-modulation approach : Review

    NARCIS (Netherlands)

    Chanput, W.; Mes, J.J.; Wichers, H.J.

    2014-01-01

    THP-1 is a human leukemia monocytic cell line, which has been extensively used to study monocyte/macrophage functions, mechanisms, signaling pathways, and nutrient and drug transport. This cell line has become a common model to estimate modulation of monocyte and macrophage activities. This review a

  4. Human Embryonic St me Cell Lines fromthe Chinese Population and Differentiation to Liver and Muscle Cell Types

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    We have established 6 hES cell lines from IVF surplus blastocysts. Characterization of these lines have shown that 4 of the 6 lines meet all of the criterion (Science) for hES cell lines and 2 of them display most characteristics of hES cells but do not form teratoma. In order to produce hES cell lines without using mouse feeders, we have produced a hES cell line using feeders derived from hES cells themselves, and showed that hES-derived feeders are capable of supporting the derivation of new hES cell line...

  5. Cytotoxicity and genotoxicity of phenazine in two human cell lines.

    Science.gov (United States)

    McGuigan, Claire F; Li, Xing-Fang

    2014-06-01

    Phenazine was recently identified as a drinking water disinfection byproduct (DBP), but little is known of its toxic effects. We examined in vitro cytotoxicity and genotoxicity of phenazine (1.9-123 μM) in HepG2 and T24 cell lines. Cytotoxicity was determined by an impedance-based real-time cell analysis instrument. The BrdU (5-bromo-2'-deoxyuridine) proliferation and MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) viability assays were used to examine mechanisms of cytotoxicity. Genotoxicity was determined using the alkaline comet assay. Concentration-dependent cytotoxicity was observed in HepG2 cells, primarily due to an antiproliferative effect (BrdU 24 h IC50: 11 μM; 48 h IC50: 7.8 μM) observed as low as 1.9 μM. T24 cells experienced a minor antiproliferative effect (BrdU 24 h IC50: 47 μM; 48 h IC50: 17 μM). IC50 values for HepG2 proliferation and viability were 54-77% lower compared to T24 cells. In both cell lines, IC50 values for proliferation were 66-90% lower than those for viability. At phenazine concentrations producing equivalent cytotoxicity, HepG2 cells (1.9-30.8 μM) experienced no significant genotoxic effects, while T24 cells (7.7-123 μM) experienced significant genotoxicity at ⩾61.5 μM. While these effects were seen at phenazine concentrations above those found in disinfected water, the persistence of the antiproliferative effect and the differential toxicity in each cell line deserves further study.

  6. Effect of cell confluence on production of cloned mice using an inbred embryonic stem cell line.

    Science.gov (United States)

    Gao, Shaorong; McGarry, Michelle; Ferrier, Tricia; Pallante, Benedetta; Priddle, Helen; Gasparrini, Bianca; Fletcher, Judy; Harkness, Linda; De Sousa, Paul; McWhir, Jim; Wilmut, Ian

    2003-02-01

    Mice have been successfully cloned from both somatic cells and hybrid embryonic stem (ES) cells. Heterozygosity of the donor ES cell genome has been suggested as a crucial factor for long-term survival of cloned mice. In the present study, an inbred ES cell line, HM-1 (129/Ola), and a well-tested ES cell line, R1 (129/Sv x 129/Sv-CP), were used as donor cells to evaluate the developmental potential of nuclear transfer embryos. We found that ES cell confluence dramatically affects the developmental potential of reconstructed embryos. With the ES cell line HM-1 and 80-90% confluence, 49% of reconstructed embryos developed to the morula/blastocyst stage, 9% of these embryos developed to live pups when transferred to the surrogate mothers, and 5 of 18 live pups survived to adulthood. By contrast, at 60-70% confluence, only 22% of embryos developed to the morula/blastocyst stage, and after transfer, only a single fetus reached term. Consistent with previous reports, the nuclei of R1 ES cells were also shown to direct development to term, but no live pups were derived from cells at later passages (>20). Our results show that the developmental potential of reconstructed embryos is determined by both cell confluence and cell passage. These results also demonstrate that the inbred ES cell line, HM-1, can be used to produce viable cloned mice, although less efficiently than most heterozygous ES cell lines.

  7. Relation of cell proliferation to expression of peripheral benzodiazepine receptors in human breast cancer cell lines.

    Science.gov (United States)

    Beinlich, A; Strohmeier, R; Kaufmann, M; Kuhl, H

    2000-08-01

    Peripheral benzodiazepine receptor (PBR) agonist [(3)H]Ro5-4864 has been shown to bind with high affinity to the human breast cancer cell line BT-20. Therefore, we investigated different human breast cancer cell lines with regard to binding to [(3)H]Ro5-4864 and staining with the PBR-specific monoclonal antibody 8D7. Results were correlated with cell proliferation characteristics. In flow cytometric analysis, the estrogen receptor (ER)-negative breast cancer cell lines BT-20, MDA-MB-435-S, and SK-BR-3 showed significantly higher PBR expression (relative fluorescence intensity) than the ER-positive cells T47-D, MCF-7 and BT-474 (Pdiazepam-binding inhibitor are possibly involved in the regulation of cell proliferation of human breast cancer cell lines.

  8. In vitro holding and PLD-repair. Pt. 2. A flow cytometric and electron microscopic analysis of some mammalian cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, A.F.G. (Institute for Basic Research in Developmental Disabilities, Staten Island, NY (USA)); Palackal, T. (State Univ. of New York, Brooklyn, NY (USA). Div. of Radiobiology); Lange, C.S. (Kiel Univ. (Germany, F.R.). Abt. Frauenheilkunde)

    1989-12-01

    The repair of potentially lethal damage (PLDR) in mammalian cells is expected to be better in quiescent cultures since PLD is supposedly fixed during cycle progression. Plateau phase cultures, therefore, serve as models because of assumed mitotic quiescence. Four established cell lines (V79, CHO, L5178Y and HELA) and one euploid cell strain IMR-90 have been analysed by flow cytometry and electron microscopy to address questions on quiescence in the plateau phase and the effect of holding (induction of quiescence by nutrient privation). In contrast to commonly held views, our results indicate that the quiescent fraction in cultures from transformed cells is exceedingly low (1% or less). Plateau phase cultures of transformed cells are constantly turning over. Euploid cells like the IMR-90 show true quiescence in the plateau phase. Holding causes typical cytopathological changes. These changes have been ultrastructurely characterised. Resistant sub-populations of cells can be selected out under holding-conditions. Such selected cells show completely different radiobiological characteristics, which raise questions on the interpretation of data on PLDR. (orig.).

  9. Mitochondrial DNA sequence analysis of two mouse hepatocarcinoma cell lines

    Institute of Scientific and Technical Information of China (English)

    Ji-Gang Dai; Xia Lei; Jia-Xin Min; Guo-Qiang Zhang; Hong Wei

    2005-01-01

    AIM: To study genetic difference of mitochondrial DNA (mtDNA)between two hepatocarcinoma cell lines (Hca-F and Hca-P)with diverse metastatic characteristics and the relationship between mtDNA changes in cancer cells and their oncogenic phenotype.METHODS: Mitochondrial DNA D-loop, tRNAMet+Glu+Ile and ND3gene fragments from the hepatocarcinoma cell lines with 1100, 1126 and 534 bp in length respectively were analysed by PCR amplification and restriction fragment length polymorphism techniques. The D-loop 3' end sequence of the hepatocarcinoma cell lines was determined by sequencing.RESULTS: No amplification fragment length polymorphism and restriction fragment length polymorphism were observed in tRNAMet+Glu+Ile,ND3 and D-loop of mitochondrial DNA of the hepatocarcinoma cells. Sequence differences between Hca-F and Hca-P were found in mtDNA D-loop.CONCLUSION: Deletion mutations of mitochondrial DNA restriction fragment may not play a significant role in carcinogenesis. Genetic difference of mtDNA D-loop between Hca-F and Hca-P, which may reflect the environmental and genetic influences during tumor progression, could be linked to their tumorigenic phenotypes.

  10. Centrosomal dysregulation in human metastatic melanoma cell lines.

    Science.gov (United States)

    Charters, Geoffrey A; Stones, Clare J; Shelling, Andrew N; Baguley, Bruce C; Finlay, Graeme J

    2011-09-01

    Correct partitioning of the replicated genome during mitosis is orchestrated by centrosomes, and chromosomal instability is a commonly reported feature of human cancer. Melanomas are notorious for their genetic instability and rapid clonal evolution that may be manifested as aggressive growth and facile generation of therapy-resistant variants. We characterized the centrosomal status, ploidy, and gene status (TP53, CDKN2A/B, BRAF, and NRAS) of 15 human metastatic melanoma cell lines. Cells were labelled for pericentrin (a centrosomal marker), DNA and α-tubulin, and scored for centrosome morphology, supernumerary centrosomes, and mitotic symmetry. The incidence of supernumerary centrosomes correlated with that of gross centrosomal abnormalities (r = 0.90), mitotic asymmetry (r = 0.90), and, surprisingly, increased content of G/M cells (r = 0.79). Centrosomal numerical dysregulation, observed in all cell lines, was found not to be specifically related to the status of any of the characterized gene mutations that were found in 13/15 cell lines. We conclude that centrosomal dysregulation may arise from multiple mechanisms and may drive the generation of genetic and phenotypic diversity in melanoma.

  11. BRITER: a BMP responsive osteoblast reporter cell line.

    Directory of Open Access Journals (Sweden)

    Prem Swaroop Yadav

    Full Text Available BACKGROUND: BMP signaling pathway is critical for vertebrate development and tissue homeostasis. High-throughput molecular genetic screening may reveal novel players regulating BMP signaling response while chemical genetic screening of BMP signaling modifiers may have clinical significance. It is therefore important to generate a cell-based tool to execute such screens. METHODOLOGY/PRINCIPAL FINDINGS: We have established a BMP responsive reporter cell line by stably integrating a BMP responsive dual luciferase reporter construct in the immortalized calvarial osteoblast cells isolated from tamoxifen inducible Bmp2; Bmp4 double conditional knockout mouse strain. This cell line, named BRITER (BMP Responsive Immortalized Reporter cell line, responds robustly, promptly and specifically to exogenously added BMP2 protein. The sensitivity to added BMP may be further increased by depleting the endogenous BMP2 and BMP4 proteins. CONCLUSION: As the dynamic range of the assay (for BMP responsiveness is very high for BRITER and as it responds specifically and promptly to exogenously added BMP2 protein, BRITER may be used effectively for chemical or molecular genetic screening for BMP signaling modifiers. Identification of novel molecular players capable of influencing BMP signaling pathway may have clinical significance.

  12. Differences in radiosensitivity between three HER2 overexpressing cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Ann-Charlott; Tolmachev, Vladimir; Stenerloew, Bo [Uppsala University, Unit of Biomedical Radiation Sciences, Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, Uppsala (Sweden); Goestring, Lovisa [Affibody AB, Bromma (Sweden); Palm, Stig [Sahlgrenska Academy at Goeteborg University, Department of Radiation Physics, Goeteborg (Sweden); Carlsson, Joergen [Uppsala University, Unit of Biomedical Radiation Sciences, Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, Uppsala (Sweden); Rudbeck Laboratory, Biomedical Radiation Sciences, Uppsala (Sweden)

    2008-06-15

    HER2 is a potential target for radionuclide therapy, especially when HER2 overexpressing breast cancer cells are resistant to Herceptin {sup registered} treatment. Therefore, it is of interest to analyse whether HER2 overexpressing tumour cells have different inherent radiosensitivity. The radiosensitivity of three often used HER2 overexpressing cell lines, SKOV-3, SKBR-3 and BT-474, was analysed. The cells were exposed to conventional photon irradiation, low linear energy transfer (LET), to characterise their inherent radiosensitivity. The analysis was made with clonogenic survival and growth extrapolation assays. The cells were also exposed to alpha particles, high LET, from {sup 211}At decays using the HER2-binding affibody molecule {sup 211}At-(Z{sub HER2:4}){sub 2} as targeting agent. Assays for studies of internalisation of the affibody molecule were applied. SKOV-3 cells were most radioresistant, SKBR-3 cells were intermediate and BT-474 cells were most sensitive as measured with the clonogenic and growth extrapolation assays after photon irradiation. The HER2 dependent cellular uptake of {sup 211}At was qualitatively similar for all three cell lines. However, the sensitivity to the alpha particles from {sup 211}At differed; SKOV-3 was most resistant, SKBR-3 intermediate and BT-474 most sensitive. These differences were unexpected because it is assumed that all types of cells should have similar sensitivity to high-LET radiation. The sensitivity to alpha particle exposure correlated with internalisation of the affibody molecule and with size of the cell nucleus. There can be differences in radiosensitivity, which, if they also exist between patient breast cancer cells, are important to consider for both conventional radiotherapy and for HER2-targeted radionuclide therapy. (orig.)

  13. Effect of 8-Chloroadenosine on Undifferentiatied HL-60 Cell Line

    Institute of Scientific and Technical Information of China (English)

    CUIJing-rong; HUIYu; XIANGYou-qing; ZHANGLi-he

    2003-01-01

    Aim To study the effect of 8-chloroadenosine (8-CA)on undifferentiatied HL-60 cell line. Methods The IC50 of cancer cell proliferation was determined using a microculture plate reader at 570 nm (MTT) and 540 nm (SRB).Morphology of HL-60 cells was observed under a scanning electron microscope and a transmission electron microscope. The differentiation of HL-60 cells was examined by nitro blue tetrazolium reduction (NBT) and acid phosphatase assay. The cycle of HL-60 cells was analyzed by flow cytometry. Results 8-CA inhibited proliferation of eight human cancer cell lines.The IC50 ranked in the following order; KB (0.05 μmol·L-1 ) < HL-60 (0.25 μmol·L-1) < Bel-7402 (0.56μmol·L-1 )< MCF-7 (0.65μmol·L-1) < HCT (0.79 μmol·L-1) < HeLa (0.89μmol·L-1) < BGC-823 ( 1.149μmol·L-1) cell surface shortened, and the shape of HL-60 cells nuclei changed to kidney-shaped, horse shoe-shaped and bilob ated after treatment with 8-CA. Meanwhile, 8-CA promoted NBT reduction and increased activity of acid phosphatase in HL-60 ceils in a time and concentration-dependent manner. Flow cytometry analysis indicated that 8-CA induced an appreciable increase of the cell population in G1 phase with a marked reduction in S phase. Conclusion 8-CA can induce differentiation of HL-60 cells and block the cells at G1 phase, thus inhibiting proliferation of HL-60 cells.

  14. Plasmids and packaging cell lines for use in phage display

    Science.gov (United States)

    Bradbury, Andrew M.

    2012-07-24

    The invention relates to a novel phagemid display system for packaging phagemid DNA into phagemid particles which completely avoids the use of helper phage. The system of the invention incorporates the use of bacterial packaging cell lines which have been transformed with helper plasmids containing all required phage proteins but not the packaging signals. The absence of packaging signals in these helper plasmids prevents their DNA from being packaged in the bacterial cell, which provides a number of significant advantages over the use of both standard and modified helper phage. Packaged phagemids expressing a protein or peptide of interest, in fusion with a phage coat protein such as g3p, are generated simply by transfecting phagemid into the packaging cell line.

  15. Design, synthesis, crystallization and biological evaluation of new symmetrical biscationic compounds as selective inhibitors of human Choline Kinase α1 (ChoKα1)

    Science.gov (United States)

    Schiaffino-Ortega, Santiago; Baglioni, Eleonora; Mariotto, Elena; Bortolozzi, Roberta; Serrán-Aguilera, Lucía; Ríos-Marco, Pablo; Carrasco-Jimenez, M. Paz; Gallo, Miguel A.; Hurtado-Guerrero, Ramon; Marco, Carmen; Basso, Giuseppe; Viola, Giampietro; Entrena, Antonio; López-Cara, Luisa Carlota

    2016-03-01

    A novel family of compounds derivative of 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bispyridinium or -bisquinolinium bromide (10a-l) containing a pair of oxygen atoms in the spacer of the linker between the biscationic moieties, were synthesized and evaluated as inhibitors of choline kinase against a panel of cancer-cell lines. The most promising compounds in this series were 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))bis(4-(dimethylamino)pyridinium) bromide (10a) and 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bis(7-chloro-4-(pyrrolidin-1-yl)quinolinium) bromide (10l), which inhibit human choline kinase (ChoKα1) with IC50 of 1.0 and 0.92 μM, respectively, in a range similar to that of the previously reported biscationic compounds MN58b and RSM932A. Our compounds show greater antiproliferative activities than do the reference compounds, with unprecedented values of GI50 in the nanomolar range for several of the cancer-cell lines assayed, and more importantly they present low toxicity in non-tumoral cell lines, suggesting a cancer-cell-selective antiproliferative activity. Docking studies predict that the compounds interact with the choline-binding site in agreement with the binding mode of most previously reported biscationic compounds. Moreover, the crystal structure of ChoKα1 with compound 10a reveals that this compound binds to the choline-binding site and mimics HC-3 binding mode as never before.

  16. Survey of Differentially Methylated Promoters in Prostate Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Yipeng Wang

    2005-08-01

    Full Text Available DNA methylation, copy number in the genomes of three immortalized prostate epithelial, five cancer cell lines (LNCaP, PC3, PC3M, PC3M-Pro4, PC3MLN4 were compared using a microarray-based technique. Genomic DNA is cut with a methylation-sensitive enzyme Hpall, followed by linker ligation, polymerase chain reaction (PCR amplification, labeling, hybridization to an array of promoter sequences. Only those parts of the genomic DNA that have unmethylated restriction sites within a few hundred base pairs generate PCR products detectable on an array. Of 2732 promoter sequences on a test array, 504 (18.5% showed differential hybridization between immortalized prostate epithelial, cancer cell lines. Among candidate hypermethylated genes in cancer-derived lines, there were eight (CD44, CDKN1A, ESR1, PLAU, RARB, SFN, TNFRSF6, TSPY previously observed in prostate cancer, 13 previously known methylation targets in other cancers (ARHI, bcl-2, BRCA1, CDKN2C, GADD45A, MTAP, PGR, SLC26A4, SPARC, SYK, TJP2, UCHL1, WIT-1. The majority of genes that appear to be both differentially methylated, differentially regulated between prostate epithelial, cancer cell lines are novel methylation targets, including PAK6, RAD50, TLX3, PIR51, MAP2K5, INSR, FBN1, GG2-1, representing a rich new source of candidate genes used to study the role of DNA methylation in prostate tumors.

  17. Highly efficient site-specific transgenesis in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Michael Iacovos P

    2012-12-01

    Full Text Available Abstract Background Transgenes introduced into cancer cell lines serve as powerful tools for identification of genes involved in cancer. However, the random nature of genomic integration site of a transgene highly influences the fidelity, reliability and level of its expression. In order to alleviate this bottleneck, we characterized the potential utility of a novel PhiC31 integrase-mediated site-specific insertion system (PhiC31-IMSI for introduction of transgenes into a pre-inserted docking site in the genome of cancer cells. Methods According to this system, a “docking-site” was first randomly inserted into human cancer cell lines and clones with a single copy were selected. Subsequently, an “incoming” vector containing the gene of interest was specifically inserted in the docking-site using PhiC31. Results Using the Pc-3 and SKOV-3 cancer cell lines, we showed that transgene insertion is reproducible and reliable. Furthermore, the selection system ensured that all surviving stable transgenic lines harbored the correct integration site. We demonstrated that the expression levels of reporter genes, such as green fluorescent protein and luciferase, from the same locus were comparable among sister, isogenic clones. Using in vivo xenograft studies, we showed that the genetically altered cancer cell lines retain the properties of the parental line. To achieve temporal control of transgene expression, we coupled our insertion strategy with the doxycycline inducible system and demonstrated tight regulation of the expression of the antiangiogenic molecule sFlt-1-Fc in Pc-3 cells. Furthermore, we introduced the luciferase gene into the insertion cassette allowing for possible live imaging of cancer cells in transplantation assays. We also generated a series of Gateway cloning-compatible intermediate cassettes ready for high-throughput cloning of transgenes and demonstrated that PhiC31-IMSI can be achieved in a high throughput 96-well plate

  18. Establishment of Mammalian Cell Lines for Constitutive Expression of Influenza Virus Matrix Protein 2%稳定表达流感病毒基质蛋白2的哺乳动物细胞系的建立

    Institute of Scientific and Technical Information of China (English)

    陈爱珺; 郭建强; 姚立红; 殷继永; 张智清

    2013-01-01

    To establish a mammalian cell line for stable expression of the matrix protein 2 (M2) of influenza virus type A. M2 gene was amplified by PCR from the influenza virus strain A/PR/8/34. The PCR product was cloned into eukaryotic expression vector pcDNA5/FRT. After identification with restriction enzyme digestion, the plasmid was co-transfected with plasmid pOG44 which expressed Flp in Flp-In-CHO cells. The target gene was integrated into chromosome of CHO cells by homologous recombination in vivo. Recombinant CHO-M2 cell lines were selected for hygromycin B resistance. A total of 15 recombinant cell strains with high expression of M2 protein were screened by hygromycin, and the expression of M2 protein was determined by IFA and Western blot. After subculturing for 10 passages, the presence of M2 gene in the CHO-M2 cells was confirmed by PCR, and the expression of M2 protein were proved by IFA and Western blot. We successfully constructed a mammalian cell line which stably expressed M2 protein of influenza virus type A. The cell line will be useful for studies on function of M2 protein and provide tools for novel nfluenza virus vaccine development.%本研究构建了稳定表达甲型流感病毒基质蛋白2(M2)的哺乳动物细胞系.应用PCR方法扩增A/PR/8/34(H1N1)株流感病毒M2基因,将其克隆至真核表达载体pcDNA5/FRT(pDF)上,构建出pDF-M2重组质粒.将鉴定正确的pDF M2与表达Flp重组酶的pOG44质粒共转染Flp-In-CHO细胞,通过体内同源重组使目的基因整合到宿主细胞染色体上.筛选具有Hygromycin B抗性的重组细胞株命名为CHO-M2.以间接免疫荧光法(IFA)和Western blot法检测M2的表达,共获得15株高表达M2蛋白的重组细胞株.这些重组细胞株在连续培养10代后,PCR方法仍可检测到M2基因的存在,IFA也检测到蛋白的稳定表达.本研究成功获得了稳定表达甲型流感病毒M2的哺乳动物细胞系,为M2蛋白的功能研究和非复制型流感病毒疫苗的研制提供了新的工具.

  19. Derivation of Human Skin Fibroblast Lines for Feeder Cells of Human Embryonic Stem Cells.

    Science.gov (United States)

    Unger, Christian; Felldin, Ulrika; Rodin, Sergey; Nordenskjöld, Agneta; Dilber, Sirac; Hovatta, Outi

    2016-02-03

    After the first derivations of human embryonic stem cell (hESC) lines on fetal mouse feeder cell layers, the idea of using human cells instead of mouse cells as feeder cells soon arose. Mouse cells bear a risk of microbial contamination, and nonhuman immunogenic proteins are absorbed from the feeders to hESCs. Human skin fibroblasts can be effectively used as feeder cells for hESCs. The same primary cell line, which can be safely used for up to 15 passages after stock preparations, can be expanded and used for large numbers of hESC derivations and cultures. These cells are relatively easy to handle and maintain. No animal facilities or animal work is needed. Here, we describe the derivation, culture, and cryopreservation procedures for research-grade human skin fibroblast lines. We also describe how to make feeder layers for hESCs using these fibroblasts.

  20. Correlation between Twist expression and multidrug resistance of breast cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Yue-Xi Wang; Xiao-Mei Chen; Jun Yan; Zhi-Ping Li

    2016-01-01

    Objective:To study the correlation between Twist expression and multidrug resistance of breast cancer cell lines. Methods:Human breast cancer cell lines MCF-7, cisplatin-resistant human breast cancer cell lines MCF-7/DDP, doxorubicin-resistant human breast cancer cell lines MCF-7/Adr and taxol-resistant human breast cancer cell lines MCF/PTX were cultured, Twist in human breast cancer cell lines MCF-7 was overexpressed and treated with doxorubicin, and then cell viability and expression levels of EMT marker molecules and related signaling pathway molecules were detected. Results:mRNA contents and protein contents of Twist in drug-resistant breast cancer cell lines MCF-7/DDP, MCF-7/Adr and MCF/PTX were higher than those in MCF-7 cell lines;after doxorubicin treatment, inhibitory rates of cell viability in MCF-7 cell lines were higher than those in MCF-7/Adr and MCF-7/Twist cell lines;E-cadherin expression levels in MCF-7/Adr cell lines and MCF-7/Twist cell lines were lower than those in MCF-7 cell lines, and mRNA contents and protein contents of N-cadherin, Vimentin, TGF-β, Smad, Wnt,β-catenin, TNF-αand NF-kB were higher than those in MCF-7 cell lines. Conclusion:Increased expression of Twist is associated with the occurrence of drug resistance in breast cancer cells.

  1. "Helicobacter Pylori Attachment To 7 Mamalian Cell Lines "

    Directory of Open Access Journals (Sweden)

    N. Rahimi-Fard

    2006-06-01

    Full Text Available Background and Aim: Helicobacter pylori is the etiologic agent of chronic –active gastritis, gastroduodenal ulcers in humans, and a co-factor in the occurrence of gastric cancer and mucosa-associated lymphoid tumors, Adhesion of H.pylori to the gastric mucosa is a critical and also initial step in the pathogenesis of the disease. Bacterial adhesion inhibitory agents provide a novel pharmacologic approach to the management of infectious diseases. Materials and Methods: 22 H. pylori strains, isolated from the antral biopsies of 49 patients with dyspepsia, gastritis, gastric ulcer, duodenal ulcer,…were assayed by ELISA (UPRto investigate the diversity of attachment to 7 mamalian cell lines. Results: The concentration of H.pylori and cell suspention ,the condition and temperature, can alter the attachment rate.Best bacterial concentration was equal to 1 Mc farland,and for cell suspension was 5*10 cells/ml.90 minutes in 37C incubation period result in maximum attachment. H.pylori can attach to all 7 cell lines, there are no significant differences between 22 H.pylori strains in attachment to cells. The attachment pattern of H.pylori to the cells showed significant reduction respectly from HepII, HeLa, SW742, AGS,HT29/219, HT29 to Caco-2.Maximum attachment were seen to HepII, HeLa and SW742 cells, and among these HepII was the best cells for this purpose. Conclusion: Our studies suggest that Hep II, HeLa and SW742 cells could serve as a suitable in-vitro model for the study of H.pylori adhesions, attachment, inhibition of attachment and detachment assays and among these Hep II cell is prefer recommended.

  2. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B

    1999-01-01

    for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  3. The Products of the Thermal Decomposition of CH3CHO

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliou, AnGayle; Piech, Krzysztof M.; Zhang, Xu; Nimlos, Mark R.; Ahmed, Musahid; Golan, Amir; Kostko, Oleg; Osborn, David L.; Daily, John W.; Stanton, John F.; Ellison, G. Barney

    2011-04-06

    We have used a heated 2 cm x 1 mm SiC microtubular (mu tubular) reactor to decompose acetaldehyde: CH3CHO + DELTA --> products. Thermal decomposition is followed at pressures of 75 - 150 Torr and at temperatures up to 1700 K, conditions that correspond to residence times of roughly 50 - 100 mu sec in the mu tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: VUV photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscopy after isolation in a cryogenic matrix. Besides CH3CHO, we have studied three isotopologues, CH3CDO, CD3CHO, and CD3CDO. We have identified the thermal decomposition products CH3(PIMS), CO (IR, PIMS), H (PIMS), H2 (PIMS), CH2CO (IR, PIMS), CH2=CHOH (IR, PIMS), H2O (IR, PIMS), and HC=CH (IR, PIMS). Plausible evidence has been found to support the idea that there are at least three different thermal decomposition pathways for CH3CHO: Radical decomposition: CH3CHO + DELTA --> CH3 + [HCO] --> CH3 + H + CO Elimination: CH3CHO + DELTA --> H2 + CH2=C=O. Isomerization/elimination: CH3CHO + DELTA --> [CH2=CH-OH] --> HC=CH + H2O. Both PIMS and IR spectroscopy show compelling evidence for the participation of vinylidene, CH2=C:, as an intermediate in the decomposition of vinyl alchohol: CH2=CH-OH + DELTA --> [CH2=C:] + H2O --> HC=CH + H2O.

  4. Feeder-independent continuous culture of the PICM-19 pig liver stem cell line

    Science.gov (United States)

    The PICM-19 pig liver stem cell line is a bipotent cell line, i.e., capable of forming either bile ductules or hepatocyte monolayers in vitro, that was derived from the primary culture of pig embryonic stem cells. The cell line has been strictly feeder-dependent in that cell replication morphology,...

  5. Cytolytic replication of echoviruses in colon cancer cell lines

    Directory of Open Access Journals (Sweden)

    Gullberg Maria

    2011-10-01

    Full Text Available Abstract Background Colorectal cancer is one of the most common cancers in the world, killing nearly 50% of patients afflicted. Though progress is being made within surgery and other complementary treatments, there is still need for new and more effective treatments. Oncolytic virotherapy, meaning that a cancer is cured by viral infection, is a promising field for finding new and improved treatments. We have investigated the oncolytic potential of several low-pathogenic echoviruses with rare clinical occurrence. Echoviruses are members of the enterovirus genus within the family Picornaviridae. Methods Six colon cancer cell lines (CaCo-2, HT29, LoVo, SW480, SW620 and T84 were infected by the human enterovirus B species echovirus 12, 15, 17, 26 and 29, and cytopathic effects as well as viral replication efficacy were investigated. Infectivity was also tested in spheroids grown from HT29 cells. Results Echovirus 12, 17, 26 and 29 replicated efficiently in almost all cell lines and were considered highly cytolytic. The infectivity of these four viruses was further evaluated in artificial tumors (spheroids, where it was found that echovirus 12, 17 and 26 easily infected the spheroids. Conclusions We have found that echovirus 12, 17 and 26 have potential as oncolytic agents against colon cancer, by comparing the cytolytic capacity of five low-pathogenic echoviruses in six colon cancer cell lines and in artificial tumors.

  6. Genetic instability of cell lines derived from a single human small cell carcinoma of the lung

    DEFF Research Database (Denmark)

    Engelholm, S A; Vindeløv, L L; Spang-Thomsen, M

    1985-01-01

    Specimens from a human small cell carcinoma of the lung were established as a cell line in vitro. Flow cytometric DNA analysis demonstrated only one tumor cell population in the parent tumor as well as in the early passages in vitro. After six passages in vitro, two new subpopulations with differ......Specimens from a human small cell carcinoma of the lung were established as a cell line in vitro. Flow cytometric DNA analysis demonstrated only one tumor cell population in the parent tumor as well as in the early passages in vitro. After six passages in vitro, two new subpopulations...

  7. Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-r...

  8. Regulation of cholesterol synthesis in four colonic adenocarcinoma cell lines.

    Science.gov (United States)

    Cerda, S R; Wilkinson, J; Broitman, S A

    1995-12-01

    Colon tumor cells, unlike normal human fibroblasts, exhibited an uncoupling of low density lipoprotein (LDL)-derived cholesterol from cellular growth, when endogenous cholesterol synthesis was inhibited by mevinolin, a hydroxymethylglutaryl-CoA reductase (HMG-CoAR) competitive inhibitor [Fabricant, M., and Broitman, S.A. (1990) Cancer Res. 50, 632-636]. Further evaluation of cholesterol metabolism was conducted in two undifferentiated (SW480, SW1417) and two differentiated (HT29, CACO2) colonic adenocarcinoma (adeno-CA) cell lines and an untransformed human fibroblast, AG1519A. Cells grown in monolayer culture to near subconfluency were used to assess endogenous cholesterol synthesis by 14C-acetate incorporation, in response to the following treatments in lipoprotein-deficient serum (LPDS)-supplemented minimum essential medium (MEM): LPDS alone, LDL, mevinolin, mevinolin with LDL, and 25-hydroxy-cholesterol (25-OH-CH). Complete fetal bovine serum (FBS)-supplemented MEM was used as control. All colon tumor lines exhibited similarly high endogenous cholesterol synthesis in both FBS and LPDS relative to the fibroblasts which demonstrated low basal levels in FBS and maximal synthesis in LPDS. LDL treatment did not inhibit cholesterol synthesis in colon tumor cells, but suppressed that in the fibroblast by 70%. Sterol repression of cholesterol synthesis mediated by 25-OH-CH occurred in all cells. Mevinolin caused a reduction in cholesterol synthesis in the colonic cancer cell lines, which was not further decreased by concurrent addition of LDL. In contrast, in mevinolin-treated fibroblasts, LDL further inhibited cholesterol synthesis. When the effect of cell density on cholesterol synthesis regulation was evaluated under conditions of sparse density in SW480 and SW147, results indicated that (i) basal rates of cholesterol synthesis were higher, (ii) LDL inhibited cholesterol synthesis more effectively, and (iii) mevinolin or 25-OH-CH had a more pronounced effect than in

  9. Derivation of human embryonic stem cell lines from parthenogenetic blastocysts

    Institute of Scientific and Technical Information of China (English)

    Qingyun Mai; Yang Yu; Tao Li; Liu Wang; Mei-jue Chen; Shu-zhen Huang; Canquan Zhou; Qi Zhou

    2007-01-01

    Parthenogenesis is one of the main, and most useful, methods to derive embryonic stem cells (ESCs), which may be an important source of histocompatible cells and tissues for cell therapy. Here we describe the derivation and characterization of two ESC lines (hPES-1 and hPES-2) from in vitro developed blastocysts following parthenogenetic activation of human oocytes. Typical ESC morphology was seen, and the expression of ESC markers was as expected for alkaline phosphatase, octamer-binding transcription factor 4, stage-specific embryonic antigen 3, stage-specific embryonic antigen 4, TRA-1-60, and TRA-1-81, and there was absence of expression of negative markers such as stage-specific embryonic antigen 1. Expression of genes specific for different embryonic germ layers was detected from the embryoid bodies (EBs) of both hESC lines, suggesting their differentiation potential in vitro. However, in vivo, only hPES-1 formed teratoma consisting of all three embryonic germ layers (hPES-2 did not). Interestingly, after continuous proliferation for more than 100 passages, hPES-1 cells still maintained a normal 46 XX karyotype; hPES-2 displayed abnormalities such as chromosome translocation after long term passages. Short Tandem Repeat (STR) results demonstrated that the hPES lines were genetic matches with the egg donors, and gene imprinting data confirmed the parthenogenetic origin of these ES cells. Genome-wide SNP analysis showed a pattern typical of parthenogenesis. All of these results demonstrated the feasibility to isolate and establish human parthenogenetic ESC lines, which provides an important tool for studying epigenetic effects in ESCs as well as for future therapeutic interventions in a clinical setting.

  10. Regulation of osteoprotegerin expression by Notch signaling in human oral squamous cell carcinoma cell line

    Institute of Scientific and Technical Information of China (English)

    Jeeranan Manokawinchoke; Thanaphum Osathanon; Prasit Pavasant

    2016-01-01

    Objective: To investigate the influence of Notch signaling on osteoprotegerin (OPG) expression in a human oral squamous cell carcinoma cell line. Methods: Activation of Notch signaling was performed by seeding cells on Jagged1 immobilized surfaces. In other experiments, a γ-secretase inhibitor was added to the culture medium to inhibit intracellular Notch signaling. OPG mRNA and protein were determined by real-time PCR and ELISA, respectively. Finally, publicly available microarray database analysis was performed using connection up- or down-regulation expression analysis of microarrays software. Results: Jagged1-treatment of HSC-4 cells enhanced HES1 and HEY1 mRNA expres-sion, confirming the intracellular activation of Notch signaling. OPG mRNA and protein levels were significantly suppressed upon Jagged1 treatment. Correspondingly, HSC-4 cells treated with a γ-secretase inhibitor resulted in a significant reduction of HES1 and HEY1 mRNA levels, and a marked increase in OPG protein expression was observed. These results implied that Notch signaling regulated OPG expression in HSC-4 cells. However, Jagged1 did not alter OPG expression in another human oral squamous cell carcinoma cell line (HSC-5) or a human head and neck squamous cell carcinoma cell line (HN22). Conclusions: Notch signaling regulated OPG expression in an HSC-4 cell line and this mechanism could be cell line specific.

  11. Regulation of osteoprotegerin expression by Notch signaling in human oral squamous cell carcinoma cell line

    Institute of Scientific and Technical Information of China (English)

    Jeeranan Manokawinchoke; Thanaphum Osathanon; Prasit Pavasant

    2016-01-01

    Objective: To investigate the influence of Notch signaling on osteoprotegerin(OPG)expression in a human oral squamous cell carcinoma cell line.Methods: Activation of Notch signaling was performed by seeding cells on Jagged1 immobilized surfaces. In other experiments, a g-secretase inhibitor was added to the culture medium to inhibit intracellular Notch signaling. OPG m RNA and protein were determined by real-time PCR and ELISA, respectively. Finally, publicly available microarray database analysis was performed using connection up- or down-regulation expression analysis of microarrays software.Results: Jagged1-treatment of HSC-4 cells enhanced HES1 and HEY1 m RNA expression, confirming the intracellular activation of Notch signaling. OPG m RNA and protein levels were significantly suppressed upon Jagged1 treatment. Correspondingly, HSC-4 cells treated with a g-secretase inhibitor resulted in a significant reduction of HES1 and HEY1 m RNA levels, and a marked increase in OPG protein expression was observed.These results implied that Notch signaling regulated OPG expression in HSC-4 cells.However, Jagged1 did not alter OPG expression in another human oral squamous cell carcinoma cell line(HSC-5) or a human head and neck squamous cell carcinoma cell line(HN22).Conclusions: Notch signaling regulated OPG expression in an HSC-4 cell line and this mechanism could be cell line specific.

  12. Apoptosis in Raji cell line induced by influenza A virus

    Institute of Scientific and Technical Information of China (English)

    李虹; 肖丽英; 李华林; 李婉宜; 蒋中华; 张林; 李明远

    2003-01-01

    Objective To study the apoptotic effects of influenza A virus on the Raji cell line. Methods Cultured Raji cells were infected with influenza A virus at a multiplicity of infection (m.o.i) of 20 and the effects of apoptosis were detected at different time points post infection using the following methods: electron microscope, DNA agarose gel electrophoresis, PI stained flow cytometry (FCM) and Annexin-V FITC/PI stained FCM.Results Raji cells infected with influenza A virus showed changes of morphology apoptotis, DNA agarose electrophoresis also demonstrated a ladder-like pattern of DNA fragments in a time-dependent manner. PI stained FCM showed "apoptosis peak" and FITC/PI stained FCM showed apoptotic cells. Quantitative analysis indicated that the percentage of apoptotic Raji cells increased after infection, and cycloheximide (CHX), an eukaryotic transcription inhibitor, could effectively inhibit the apoptotic effects of influenza A virus in vitro.Conclusions Influenza A virus can induce apoptosis in Raji cell line suggesting that it may lead to a potential method for tumor therapy.

  13. Absence of C-type virus production in human leukemic B cell, T cell and null cell lines.

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    Ogura,Hajime

    1978-06-01

    Full Text Available Electron microscope observation of cultured human leukemic B cell, T cell and null cell lines and reverse transcriptase assay of the culture supernatants were all negative for the presence of C-type virus. Bat cell line, which propagates primate C-type viruses well, was cocultivated with the human leukemic cell lines, in the hope of amplification of virus if present. Three weeks after mixed culture, the culture supernatants were again examined for reverse transcriptase activity and the cells were tested for syncytia formation by cocultivation with rat XC, human KC and RSb cell lines. All these tests, except for the positive control using a simian sarcoma virus, were negative, suggesting that no C-type was produced from these human leukemic cell lines.

  14. Growth dynamics and cyclin expression in cutaneous T-cell lymphoma cell lines

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    Edyta Biskup

    2010-05-01

    Full Text Available We have investigated cell growth dynamics and cyclins B1 and E expression in cell lines derived from mycosis fungoides (MyLa, Sézary syndrome (SeAx, and CD30+ lympho-proliferative diseases (Mac1, Mac2a, JK. Mac1 and Mac2a had the highest growth rate (doubling time 18-28 h, >90% cycling cells whereas SeAx was proliferating slowly (doub-ling time 55 h, approximately 35% cycling cells. Expression of cyclin B1 correlated positively with doubling time whereas expression of cyclin E was unscheduled and constant across the investigated cell lines. All cell lines exhibited high expression of PCNA. Thus, we concluded that cyclin B1 could be used for rapid screening of cell proliferation in malignant lymphocytes derived from cutaneous T-cell lymphoma.

  15. Cytotoxicity of hydro-alcoholic extracts of Cucurbita pepo and Solanum nigrum on HepG2 and CT26 cancer cell lines

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    M Shokrzadeh

    2010-01-01

    Full Text Available Plants are used worldwide for the treatment of diseases, and novel drugs continue to be developed through research from plants. There are more than 20,000 species of plants used in traditional medicines, and these are all potential reservoirs for new drugs. Cucurbita pepo has been used in traditional folk medicine to treat cold and alleviate ache. Previous pharmacological tests have shown that it possesses antiviral, anti-inflammatory, and analgesic effects. Also, Solanum nigrum has been used as a diuretic and an antipyretic agent and it has also been used to cure inflammation, edema, mastitis and hepatic cancer. In this investigation, cytotoxicity of specific concentrations of hydro-alcoholic extracts of C. pepo and S. nigrum was studied on normal [Chinese hamster ovarian cells (CHO and rat fibroblast] and cancer (HepG2 and CT26 cell lines. The cytotoxic effects and IC 50 of the extracts on the selected cell lines were studied followed by colonogenic assay method. The results showed that IC 50 of S. nigrum extract was significantly lower than that of the C. pepo extract on all four cell lines (P < 0.05. On the other hand, IC 50 of S. nigrum extract was significantly higher than the extract of Taxus baccata and Cisplatin, herbal and chemical control positive anticancer compounds, respectively, on all four cell lines (P < 0.05. As a result, it is concluded that the extract of S. nigrum has almost similar cytotoxicity to the extract of T. baccata on cancer cells.

  16. Mistaken identity of widely used esophageal adenocarcinoma cell line TE-7.

    Science.gov (United States)

    Boonstra, Jurjen J; van der Velden, Albertina W; Beerens, Erwin C W; van Marion, Ronald; Morita-Fujimura, Yuiko; Matsui, Yasuhisa; Nishihira, Tetsuro; Tselepis, Chris; Hainaut, Pierre; Lowe, Anson W; Beverloo, Berna H; van Dekken, Herman; Tilanus, Hugo W; Dinjens, Winand N M

    2007-09-01

    Cancer of the esophagus is the seventh leading cause of cancer death worldwide. Esophageal carcinoma cell lines are useful models to study the biological and genetic alterations in these tumors. An important prerequisite of cell line research is the authenticity of the used cell lines because the mistaken identity of a cell line may lead to invalid conclusions. Estimates indicate that up to 36% of the cell lines are of a different origin or species than supposed. The TE series, established in late 1970s and early 1980s by Nishihira et al. in Japan, is one of the first esophageal cancer cell line series that was used throughout the world. Fourteen TE cell lines were derived from human esophageal squamous cell carcinomas and one, TE-7, was derived from a primary esophageal adenocarcinoma. In numerous studies, this TE-7 cell line was used as a model for esophageal adenocarcinoma because it is one of the few esophageal adenocarcinoma cell lines existing. We investigated the authenticity of the esophageal adenocarcinoma cell line TE-7 by xenografting, short tandem repeat profiling, mutation analyses, and array-comparative genomic hybridization and showed that cell line TE-7 shared the same genotype as the esophageal squamous cell carcinoma cell lines TE-2, TE-3, TE-12, and TE-13. In addition, for more than a decade, independent TE-7 cultures from Japan, United States, United Kingdom, France, and the Netherlands had the same genotype. Examination of the TE-7 cell line xenograft revealed the histology of a squamous cell carcinoma. We conclude that the TE-7 cell line, used in several laboratories throughout the world, is not an adenocarcinoma, but a squamous cell carcinoma cell line. Furthermore, the cell lines TE-2, TE-3, TE-7, TE-12, and TE-13 should be regarded as one single squamous cell carcinoma cell line.

  17. Establishment and characterization of primary lung cancer cell lines from Chinese population

    Institute of Scientific and Technical Information of China (English)

    Chao ZHENG; Yi-hua SUN; Xiao-lei YE; Hai-quan CHEN; Hong-bin JI

    2011-01-01

    Aim: To establish and characterize primary lung cancer cell lines from Chinese population.Methods: Lung cancer specimens or pleural effusions were collected from Chinese lung cancer patients and cultured in vitro with ACL4 medium (for non-small cell lung carcinomas (NSCLC)) or HITES medium (for small cell lung carcinomas (SCLC)) supplemented with 5%FBS. All cell lines were maintained in culture for more than 25 passages. Most of these cell lines were further analyzed for oncogenic mutations, karyotype, cell growth kinetics, and tumorigenicity in nude mice.Results: Eight primary cell lines from Chinese lung cancer patients were established and characterized, including seven NSCLC cell lines and one SCLC cell line. Five NSCLC cell lines were found to harbor epidermal growth factor receptor (EGFR) kinase domain mutations.Conclusion: These well-characterized primary lung cancer cell lines from Chinese population provide a unique platform for future studies of the ethnic differences in lung cancer biology and drug response.

  18. Efficient genetic method for establishing Drosophila cell lines unlocks the potential to create lines of specific genotypes.

    Science.gov (United States)

    Simcox, Amanda; Mitra, Sayan; Truesdell, Sharon; Paul, Litty; Chen, Ting; Butchar, Jonathan P; Justiniano, Steven

    2008-08-01

    Analysis of cells in culture has made substantial contributions to biological research. The versatility and scale of in vitro manipulation and new applications such as high-throughput gene silencing screens ensure the continued importance of cell-culture studies. In comparison to mammalian systems, Drosophila cell culture is underdeveloped, primarily because there is no general genetic method for deriving new cell lines. Here we found expression of the conserved oncogene Ras(V12) (a constitutively activated form of Ras) profoundly influences the development of primary cultures derived from embryos. The cultures become confluent in about three weeks and can be passaged with great success. The lines have undergone more than 90 population doublings and therefore constitute continuous cell lines. Most lines are composed of spindle-shaped cells of mesodermal type. We tested the use of the method for deriving Drosophila cell lines of a specific genotype by establishing cultures from embryos in which the warts (wts) tumor suppressor gene was targeted. We successfully created several cell lines and found that these differ from controls because they are primarily polyploid. This phenotype likely reflects the known role for the mammalian wts counterparts in the tetraploidy checkpoint. We conclude that expression of Ras(V12) is a powerful genetic mechanism to promote proliferation in Drosophila primary culture cells and serves as an efficient means to generate continuous cell lines of a given genotype.

  19. Efficient genetic method for establishing Drosophila cell lines unlocks the potential to create lines of specific genotypes.

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    Amanda Simcox

    2008-08-01

    Full Text Available Analysis of cells in culture has made substantial contributions to biological research. The versatility and scale of in vitro manipulation and new applications such as high-throughput gene silencing screens ensure the continued importance of cell-culture studies. In comparison to mammalian systems, Drosophila cell culture is underdeveloped, primarily because there is no general genetic method for deriving new cell lines. Here we found expression of the conserved oncogene Ras(V12 (a constitutively activated form of Ras profoundly influences the development of primary cultures derived from embryos. The cultures become confluent in about three weeks and can be passaged with great success. The lines have undergone more than 90 population doublings and therefore constitute continuous cell lines. Most lines are composed of spindle-shaped cells of mesodermal type. We tested the use of the method for deriving Drosophila cell lines of a specific genotype by establishing cultures from embryos in which the warts (wts tumor suppressor gene was targeted. We successfully created several cell lines and found that these differ from controls because they are primarily polyploid. This phenotype likely reflects the known role for the mammalian wts counterparts in the tetraploidy checkpoint. We conclude that expression of Ras(V12 is a powerful genetic mechanism to promote proliferation in Drosophila primary culture cells and serves as an efficient means to generate continuous cell lines of a given genotype.

  20. Apoptosis induced by propolis in human hepatocellular carcinoma cell line.

    Science.gov (United States)

    Choi, Y H; Lee, W Y; Nam, S Y; Choi, K C; Park, Y E

    1999-07-01

    Propolis has been reported to exhibit a wide spectrum of activities including antibiotic, antiviral, anti-inflammatory, immunostimulatory and tumor carcinostatic properties. We showed propolis induced apoptosis in a human hepatoma cell line (SNU449) by FITC-Annexin V/PI staining. We also compared the apoptosis inducing effect between Korean and Commercial (Sigma # p-1010) propolis. There was no difference on apoptosis between them.

  1. Effect of histone deacetylase inhibitor on proliferation of biliary tract cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Li-Ning Xu; Xin Wang; Sheng-Quan Zou

    2008-01-01

    AIM: To explore the effect of histone deacetylase inhibitor, trichostatin A (TSA) on the growth of biliary tract cancer cell lines (gallbladder carcinoma cell line and cholangiocarcinoma cell line) in v/vo and in vitro,and to investigate the perspective of histone deacetylase inhibitor in its clinical application.METHODS: The survival rates of gallbladder carcinoma cell line (Mz-ChA-I cell line) and cholangiocarcinoma cell lines (QBC939, KMBC and OZ cell lines) treated with various doses of TSA were detected by methylthiazoy tetrazolium (MTT) assay.A nude mouse model of transplanted gallbladder carcinoma (Mz-ChA-I cell line)was successfully established, and changes in the growth of transplanted tumor after treated with TSAwere measured.RESULTS: TSA could inhibit the proliferation of gallbladder carcinoma cell line (Mz-ChA-I cell line) and cholangiocarcinoma cell lines (QBC939, KMBC and OZ cell lines) in a dose-dependent manner.After the nude mouse model of transplanted gallbladder carcinoma (Mz-ChA-I cell line) was successfully established, the growth of cancer was inhibited in the model, after treated with TSA.CONCLUSION: TSA can inhibit the growth of cholangiocarcinoma and gallbladder carcinoma cell lines in vitro and in vivo.

  2. Pseudoislet of hybrid cellular spheroids from commercial cell lines.

    Science.gov (United States)

    Jo, Y H; Nam, B M; Kim, B Y; Nemeno, J G; Lee, S; Yeo, J E; Yang, W; Park, S H; Kim, Y S; Lee, J I

    2013-10-01

    Investigators conducting diabetes-related research have focused on islet transplantation as a radical therapy for type 1 diabetes mellitus. Pancreatic islet isolation, an essential process, is a very demanding work because of the proteolytic enzymes, species, treatment time, and individual difference. Replacement of primary isolated pancreatic islets must be carried out continuously for various in vitro tests, making primary isolated islets a useful tool for cell transplantation research. Hence, we sought to develop pseudoislets from commercial pancreas-derived cell lines. In this study, we used RIN-5F and RIN-m cells, which secrete insulin, somatostatin, or glucagon. To manufacture hybrid cellular spheroids, the cells were cultured under hanging drop plate and nonadhesive plate methods. We observed that hybrid cellular pseudoislets exhibited an oval shape, with sizes ranging from 590 to 1200 μm. Their morphology was similar to naïve islets. Cell line pseudoislets secreted and expressed insulin, glucagon, and somatostatin, as confirmed by reverse transcriptase polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry analyses. Thus, the current artificially manufactured biomimetic pseudoislets resembled pancreatic islets of the endocrine system, appearing as cellular aggregates that secreted insulin, glucagon, and somatostatin. Enhanced immunoisolation techniques may lead to the development of new islet sources for pancreatic transplantation through this pseudoislet strategy.

  3. Off-line test of the KISS gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, Yoshikazu, E-mail: yoshikazu.hirayama@kek.jp [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Watanabe, Yutaka; Imai, Nobuaki; Ishiyama, Hironobu; Jeong, Sun-Chan; Miyatake, Hiroari; Oyaizu, Michihiro [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801