Chinese Hamster Ovary cell lines

ADA BEVS BHK CHO ELISA mAb MDCK MMR SCID tPA VLP adenosine deaminase deficiency baculovirus expression vector system baby hamster kidney cell line Chinese hamster ovary cell line enzyme linked immuno sorbent assay monoclonal antibodies Madin-Darby canine kidney epithelial cells measles, mumps, rubella severe combined immunodeficiency plasminogen activator virus-like particle... 

ATP EDTA DMSO BHK CHO HEPES mAbs B Brnax MTT PEG RNA t td WHO X adenosine triphosphate ethylenediaminetetraacetic acid Dim ethylsulf oxide baby hamster kidney cell line Chinese hamster ovary cell line N-(2-hydroxyethyl)piperazine-N -(2-ethanesulphonic acid) monoclonal antibodies specific cell growth rate maximum specific cell growth rate (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide) polyethylene glycol ribonucleic acid cell culture time cell doubling time World Health Organization cell concentration... 

Acetyl-CoA ADP Ala AMP ATP BHK CC9C10 CHO CHSE CMP-NANA CoQ CoQH2 DNA acetyl-coenzyme A adenosine diphosphate alanine adenosine monophosphate adenosine triphosphate baby hamster kidney cell line hybridoma cell line Chinese hamster ovary cell line Chinook salmon embryo cell line cytosine monophosphate-N-acetylneuraminic acid coenzyme Q dihydroubiquinone deoxyribonucleic acid... 

Apart from the concentrafion of sericin, its extraction method has been shown to influence cell viability, also. If compared to heat, acid, or alkaline extraction methods, urea-extracted silk sericin is linked to the lowest cell viability of L929 mouse fibroblast (Aramwit et al., 2010). Sericin can also be used to replace bovine semm in cell freezing media. It cryopreserves cells as effectively as standard freeze medium containing foetal bovine serum. This effect has been demonstrated for various cell lines including P3U1 myeloma cell line, Chinese hamster ovary CHO cells, human dermal fibroblasts, human epidermal keratinocytes, the rat phaeochromocytoma cell line PC 12 and Sf9 insect cells (Sasaki et al., 2005), human primary hepatocytes (Miyamoto et al., 2010), rat pancreatic... 

According to a review by Walsh [10], of 165 biopharmaceuhcal products approved in the United States and Europe by 2006, only two are nucleic acid-based drugs, whereas nine of the 31 therapeutic proteins approved since 2003 are produced in E, coli, and 17 are produced by mammalian cell lines. In 2004 market distribution and manufacture of therapeutic proteins, non-glycosylated (non-antibody) proteins constitutes 40% of the total market, with 12% armual growth rate, and are produced in E. coli or the yeast Saccharomyces cerevisiae glycoproteins (primarily mAbs) constitute 60% of the total market, with 26% armual growth rate, and are produced by mammalian cell culture (mostly with cells from Chinese Hamster Ovary, or CHO). 

Results of methyl parathion assays involving effects on chromosomes have also been contradictory. For sister chromatid exchange, Waters et al. (1982) reported a positive response in Chinese hamster ovary cells only in the presence of metabolic activation system, while methyl parathion tested positive without a metabolic activation system in Chinese hamster V79 cells (Chen et al. 1981), cultured normal human lymphoid cells (Chen et al. 1981 Gomez-Arroyo et al. 1987 Sobti et al. 1982), and Burkitt s l5miphoma cells (Chen et al. 1981). Chen et al. (1981) found a significant dose-related increase in sister chromatid exchange in both hamster and human cultured cells, but dose-related cell cycle delays were less pronounced in human cell lines than in V79 cells. Negative results were obtained for chromosomal aberrations in human lymphocytes without a metabolic activation system (Kumar et al. 1993). 

Many of the initial biopharmaceuticals approved were simple replacement proteins (e.g. blood factors and human insulin). The ability to alter the amino acid sequence of a protein logically coupled to an increased understanding of the relationship between protein structure and function (Chapters 2 and 3) has facilitated the more recent introduction of several engineered therapeutic proteins (Table 1.3). Thus far, the vast majority of approved recombinant proteins have been produced in the bacterium E. coli, the yeast S. cerevisiae or in animal cell lines (most notably Chinese hamster ovary (CHO) cells or baby hamster kidney (BHK) cells. These production systems are discussed in Chapter 5. 

The biopharmaceutical sector is largely based upon the application of techniques of molecular biology and genetic engineering for the manipulation and production of therapeutic macromolecules. The majority of approved biopharmaceuticals (described from Chapter 8 onwards) are proteins produced in engineered cell lines by recombinant means. Examples include the production of insulin in recombinant E. coli and recombinant S. cerevisiae, as well as the production of EPO in an engineered (Chinese hamster ovary) animal cell line. 

Levy, L. M., Warr, D., and Attwell, D. (1998) Stoichiometry of the glial glutamate transporter GLT-1 expressed inducibly in a Chinese hamster ovary cell line selected for low endogenous Na+-dependent glutamate uptake. J. Neurosci. 18,9620-9628. 

Chinese hamster ovary cells in which there has been an extensive rearrangement of chromosome material and the chromosome number may not be constant from cell to cell, are frequently used. Polyploidy, endoreduplication and high spontaneous chromosome aberration frequencies can sometimes be found in these established cell lines, but careful cell culture techniques should minimize such effects. Cells should be treated in exponential growth when cells are in all stages of the cell cycle. 

Davies, J. and Reff, M., Chromosome localization and gene-copy-number quantification of three random integrations in Chinese-hamster ovary cells and their amplified cell lines using fluorescence in situ hybridization, Biotechnol. Appl. Biochem., 33, 99-105, 2001. 

Biopharmaceutical quantities of EPO are produced with recombinant cells. This is achieved through the isolation of the human gene that codes for EPO and transfection of the gene into cell lines such as Chinese hamster ovary cells (see Section 10.5). The product is called rhEPO—recombinant human EPO. EPO is normally administered subcutaneously and is generally well tolerated by patients. 

The most convincing example that inhibition of PC synthesis can induce apoptosis comes from a cell line with a temperature-sensitive defect in one of the enzymes in the CDP-choline pathway (Cui et al, 1996). The MT58 cell line is a Chinese hamster ovary (CHO) derived cell line with a mutation in CTP phosphocholine cytidylyltransferase (CT), which renders the... 

Vincristine resistance has been studied in Chinese hamster ovary cell lines cells resistant to vincristine also are resistant to vinblastine and vindesine. Suggestions were made that, in cells with relatively low levels of drug resistance, at least two prominent mechanisms of resistance can occur (22). In the first instance, cellular resistance may be attributable to membrane alterations that are reversible, functionally, by treatment with verapamil. In the second, resistance has been postulated to be due to an altered sensitivity of tubulin to the effects of the drugs the primary basis for postulating an altered interaction with tubulin was that a subgroup of cells resistant to vincristine showed enhanced sensitivity to taxol, a drug that can stabilize microtubules. It should be emphasized that differential sensitivities of tubulins from different tumor cells to the effects of vincristine or vinblastine has been proposed as a basis for the susceptibilities of cells to the cytotoxic effects of such drugs (23). Differences have been described in the electrophoretic patterns for tubulins obtained from vin-... 

Mammalian cells in vitro are exposed to the test chemical with and without an exogenous mammalian metaboUc activation system and cultured for two rounds of replication in bromodeox3Uiridine (BrdU) containing medium. After treatment with a spindle inhibitor (e.g., colchicine) to accumulate cells in a metaphase-Uke stage of mitosis (c-metaphase), cells are harvested, stained, and metaphase cells analyzed for SCEs. Primary cultures (e.g., human lymphocytes) or established cell lines (e.g., Chinese hamster ovary or lung cells) may be used in the assay. At least three adequately spaced concentrations of the test substance should be used. 

The simplest and most sensitive assays for detecting clastogenic (i.e. chromosomal breaking) effects involve the use of mammalian cells. Cultures of established cell lines (e.g. Chinese hamster ovary) as well as primary cell cultures (e.g. human l)nnphocyte) may be used. After exposure to a range of chemical concentrations in the presence and absence of an appropriate metabolic activation system, the cell cultures are treated with a spindle inhibitor (e.g. vinblastine) to accumulate cells in a metaphaselike stage of mitosis. Cells are harvested at appropriate times and chromosome preparations are made, stained with DNA-specific dye and the metaphase cells are analysed under the microscope for chromosome abnormalities. 

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