In vitro growth-stimulatory property of pigeon milk

1993 ◽  
Vol 71 (5-6) ◽  
pp. 303-307 ◽  
Author(s):  
L. Bharathi ◽  
K. B. Shenoy ◽  
M. Mojamdar ◽  
S. N. Hegde
Keyword(s):  
Cell Lines ◽  
Cho Cells ◽  
Cultured Cells ◽  
Guanidine Hydrochloride ◽  
Chinese Hamster ◽  
Growth Stimulation ◽  
Relative Mass ◽  
Good Growth ◽  
In Vitro Growth

Five cell lines were employed to test the growth-stimulating property of pigeon milk in vitro. All the cell lines except A431 showed good growth response to crude homogenates of pigeon milk. Enhancement of DNA synthesis in quiescent Chinese hamster ovary (CHO) cells by pigeon milk was dose dependent up to a concentration of 1%. In vitro growth stimulation by 1% pigeon milk was approximately equal to that by 2% foetal bovine serum (FBS) when CHO cells were used, growth stimulation of Vero cells by 1% pigeon milk was roughly three times of that by 2% FBS. In contrast, 1% pigeon milk was only half as active as 2% FBS on NIH/3T3 cells and five times less active than 2% FBS on human foetal lung fibroblast cells. After dialysis using a relative mass (Mr) cutoff of 3500, the pigeon milk mitogenic activity was retained in the dialyzed solution, although it decreased by 40–60% when dialyzed with Mr cutoffs of 8000 and 12 000 – 14 000. The growth-stimulating activity of pigeon milk was resistant to heat, acid, alkali, and the action of urea, guanidine hydrochloride, dithiothreitol, and trypsin. We suggest that pigeon milk is a new source of growth factor(s) capable of stimulating in vitro the growth of many mammalian cell types.Key words: pigeon milk, growth stimulation, cultured cells.

Inhibition of aflatoxin B1-induced cell injury by selenium: an in vitro study

1995 ◽  
Vol 14 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Chen-Yang Shi ◽  
Yin-Chin Hew ◽  
Choon-Nam Ong
Keyword(s):  
Dna Binding ◽  
Aflatoxin B1 ◽  
Cho Cells ◽  
Animal Studies ◽  
Cell Injury ◽  
Cultured Cells ◽  
Chinese Hamster ◽  
In Vitro Study ◽  
Cell Killing

Dietary selenium is an essential trace element in human nutrition. Selenium has been shown in animal studies to inhibit aflatoxin hepatocarcinogenesis. However, the cellu lar mechanism responsible for the inhibition has not been thoroughly studied. This study examines the effect of two selenium compounds, namely, sodium selenite and selenium- enriched yeast extract (SeY), on the cytotoxicity, DNA- binding and mutagenicity of aflatoxin B1 (AFB1) in cul tured Chinese hamster ovary (CHO) cells. CHO cells, after treatment with 2 μg ml-1 selenite or 80 μg ml-1 SeY, exhibit ed increased resistance to AFB1-induced cell killing. At a concentration of 50 μg ml-1 AFB1, cell survival, measured by the clonogenicity assay, was increased by 21- and 10- fold in selenite- and SeY-treated cells, respectively. However, selenium treatment did not appear to affect AFB1-DNA binding. Similarly, no effect was observed on AFB1 mutagenicity, as determined by the hypoxanthine- guanine phosphoribosyl transferase (HPRT) gene mutation assay. The results showed that selenium could effectively protect cells from AFB1 cytotoxicity in cultured cells but had no effect on AFB1-DNA adduct formation or mutagen esis. It is suggested that there are multiple pathways of AFB1 toxicity and that selenium can modulate AFB1- induced cell killing independent of its genotoxicity.

scholarly journals Recombinant γY278H Fibrinogen Showed Normal Secretion from CHO Cells, but a Corresponding Heterozygous Patient Showed Hypofibrinogenemia

2021 ◽  
Vol 22 (10) ◽  
pp. 5218
Author(s):  
Tomu Kamijo ◽  
Takahiro Kaido ◽  
Masahiro Yoda ◽  
Shinpei Arai ◽  
Kazuyoshi Yamauchi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cho Cells ◽  
Fibrinogen Level ◽  
Culture Media ◽  
Chinese Hamster ◽  
Plasma Fibrinogen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cho Cell ◽  
Accelerated Degradation ◽  
Heterozygous Patient

We identified a novel heterozygous hypofibrinogenemia, γY278H (Hiroshima). To demonstrate the cause of reduced plasma fibrinogen levels (functional level: 1.12 g/L and antigenic level: 1.16 g/L), we established γY278H fibrinogen-producing Chinese hamster ovary (CHO) cells. An enzyme-linked immunosorbent assay demonstrated that synthesis of γY278H fibrinogen inside CHO cells and secretion into the culture media were not reduced. Then, we established an additional five variant fibrinogen-producing CHO cell lines (γL276P, γT277P, γT277R, γA279D, and γY280C) and conducted further investigations. We have already established 33 γ-module variant fibrinogen-producing CHO cell lines, including 6 cell lines in this study, but only the γY278H and γT277R cell lines showed disagreement, namely, recombinant fibrinogen production was not reduced but the patients’ plasma fibrinogen level was reduced. Finally, we performed fibrinogen degradation assays and demonstrated that the γY278H and γT277R fibrinogens were easily cleaved by plasmin whereas their polymerization in the presence of Ca2+ and “D:D” interaction was normal. In conclusion, our investigation suggested that patient γY278H showed hypofibrinogenemia because γY278H fibrinogen was secreted normally from the patient’s hepatocytes but then underwent accelerated degradation by plasmin in the circulation.

scholarly journals 34 LIFESPAN AND CHROMOSOMAL STABILITY OF BOVINE AND PORCINE FETAL FIBROBLAST CELLS CULTURED IN VITRO

2005 ◽  
Vol 17 (2) ◽  
pp. 167 ◽  
Author(s):  
A.M. Giraldo ◽  
J.W. Lynn ◽  
C.E. Pope ◽  
R.A. Godke ◽  
K.R. Bondioli
Keyword(s):  
Cell Lines ◽  
Cultured Cells ◽  
Culture Conditions ◽  
Cycle Duration ◽  
Fibroblast Cells ◽  
Proliferative Capacity ◽  
Chromosomal Stability ◽  
Fetal Fibroblasts ◽  
Fetal Bovine

The low efficiency of nuclear transfer (NT) has been related to factors such as mitochondria heteroplasmy, failure of genomic activation, and asynchrony between the donor karyoplast and recipient cytoplast. Few studies have characterized donor cell lines in terms of proliferative capacity and chromosomal stability. It is known that suboptimal culture conditions can induce chromosomal abnormalities, and the use of aneuploid donor cells during NT can lead to a high incidence of abnormal cloned embryos (Giraldo et al. 2004 Reprod. Fertil. Dev. 16, 124 abst). The purpose of this study was to determine the lifespan and chromosomal stability of bovine and porcine fetal cells. Four bovine and four porcine fibroblast cells lines were established from 50-day and 40-day fetuses, respectively. Cells were cultured in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin and streptomycin at 37°C in 5% CO2. Each cell line was passaged to senescence. Total population doublings (PDs) and cell cycle duration were calculated. To determine the chromosome numbers at different PDs, cells were synchronized in metaphase, fixed, and stained. ANOVA and chi-square tests were used to analyze differences in PDs and proportion of aneuploid cells between cell lines, respectively (P < 0.05). The results show that proliferative capacity was not different between cell lines derived from the same species. Cell lines derived from bovine and porcine fetuses had different in vitro lifespans (33 PDs vs. 42 PDs, respectively; P < 0.05). The mean length of the cell cycles for both bovine and porcine fetal fibroblasts was ∼28 h. The percentage of aneupliod cells in both bovine and porcine fetal cell lines increased progressively with duration of culture (see Table) and was high throughout the study. The proliferative capacity of cultured cells was similar within individuals of the same species, but growth characteristics differed between fetal bovine and porcine cell lines. The progressive increase of aneuploid cells could be due to suboptimal culture conditions or unusual chromosome instability in the particular fetuses used. These data demonstrate the importance of determining chromosome content and the use of cells at early passages to decrease the percentage of aneuploid reconstructed embryos and increase the efficiency of NT.

Chinese Hamster Cell Variants Resistant to the A Chain of Ricin Carry Altered Ribosome Function

1982 ◽  
Vol 2 (6) ◽  
pp. 599-606
Author(s):  
Mayumi Ono ◽  
Michihiko Kuwano ◽  
Kei-Ichi Watanabe ◽  
Gunki Funatsu
Keyword(s):  
Protein Synthesis ◽  
Cell Lines ◽  
Cho Cells ◽  
Ricinus Communis ◽  
Ribosomal Subunit ◽  
Chinese Hamster ◽  
Resistant Cell ◽  
Cytotoxic Action ◽  
A Chain ◽  
Ricin A

Ricin, a toxic lectin from Ricinus communis , is composed of two different polypeptide chains, A and B, and the ricin A chain (RA) blocks protein synthesis. We studied cell lines resistant to cytotoxic action of RA. One low-RA-resistant cell line, AR10, isolated from Chinese hamster ovary (CHO) cells, was resistant to a low dose of RA (1 μg/ml) and showed a 10-fold-higher resistance to RA and ricin than that of CHO. We further mutagenized AR10 to isolate high-RA-resistant cell lines AR100-6, AR100-9, and AR100-13, which were resistant to higher doses of RA and ricin (100- to 1,000-fold) than CHO was. The binding of [ 125 I]ricin to AR10, AR100-6, AR100-9, and AR100-13 cells was decreased to about 30% of that of CHO. The internalization of [ 125 I]ricin in AR10 cells and in the high-RA-resistant clones was the same. Polyuridylate-dependent polyphenylalanine synthesis, using S-30 extracts from either AR100-9 or AR100-13, was about 100-fold more resistant to the inhibitory action of RA than when CHO, AR10, and AR100-6 cells extracts were used. The protein synthesis with ribosomes (80S) from AR100-9 or AR100-13 was 10- to 100-fold more resistant to RA than it was with parental ribosomes when combined with the S-100 fraction of CHO cells. The polyphenylalanine synthesis assay using the ribosomes constituted from the 60S subunit of AR100-9 and the 40S subunit of CHO indicated that the resistant phenotype of AR100-9 cells is due to an alteration of the 60S ribosomal subunit.

Suppression of tumor formation in vivo by expression of the JE gene in malignant cells

1991 ◽  
Vol 11 (6) ◽  
pp. 3125-3131
Author(s):  
B J Rollins ◽  
M E Sunday
Keyword(s):  
Cho Cells ◽  
Chinese Hamster ◽  
Suppressive Effect ◽  
Tumor Formation ◽  
Host Animal ◽  
Early Growth Response ◽  
Discernible Effect ◽  
Early Growth Response Gene

The early growth response gene JE encodes a monocyte chemoattractant, MCP-1. The JE/MCP-1 protein attracts and stimulates human monocytes and induces monocyte-mediated inhibition of tumor cell growth in vitro. Expression of human or murine JE/MCP-1 in Chinese hamster ovary (CHO) cells completely suppressed their ability to form tumors in nude mice. Coinjection of JE/MCP-1-expressing cells with nonexpressing CHO cells or with HeLa cells also prevented tumor formation. Since JE/MCP-1 expression had no discernible effect on the tranformed phenotype of these cells in vitro, the suppressive effect depends on host animal factors. These factors are likely to be components of the inflammatory response, because JE/MCP-1-expressing cells elicited a predominantly monocytic infiltrate at the site of injection. Our results suggest that JE/MCP-1 protein may be useful in cancer therapy.

scholarly journals cDNA cloning and expression of a human platelet-derived growth factor (PDGF) receptor specific for B-chain-containing PDGF molecules.

1988 ◽  
Vol 8 (8) ◽  
pp. 3476-3486 ◽  
Author(s):  
L Claesson-Welsh ◽  
A Eriksson ◽  
A Morén ◽  
L Severinsson ◽  
B Ek ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Cdna Cloning ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Cloning And Expression ◽  
Platelet Derived Growth Factor ◽  
Amino Acid Sequence Similarity ◽  
Pdgf Receptor

The structure of the human receptor for platelet-derived growth factor (PDGF) has been deduced through cDNA cloning. A 5.45-kilobase-pair cDNA clone predicts a 1,106-amino-acid polypeptide, including the cleavable signal sequence. The overall amino acid sequence similarity with the murine PDGF receptor is 85%. After transcription of the cDNA and translation in vitro, a PDGF receptor antiserum was used to immunoprecipitate a product of predicted size, which also could be phosphorylated in vitro. Stable introduction of the cDNA into Chinese hamster ovary (CHO) cells led to the expression of a 190-kilodalton component, which was immunoprecipitated by the PDGF receptor antiserum; this most probably represents the mature PDGF receptor. Binding assays with different 125I-labeled dimeric forms of PDGF A and B chains showed that the PDGF receptor expressed in CHO cells bound PDGF-BB and, to a lesser extent, PDGF-AB, but not PDGF-AA.

scholarly journals Murine Gammaherpesvirus (MHV-68) Transforms Cultured Cells in vitro

Intervirology ◽  
2015 ◽  
Vol 58 (2) ◽  
pp. 69-72 ◽  
Author(s):  
Veronika Mrázová ◽  
Tatiana Betáková ◽  
Marcela Kúdelová ◽  
Miroslava Šupolíková ◽  
Veronika Lachová ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cultured Cells ◽  
Virus Antigen ◽  
Immunofluorescence Assay ◽  
Dermal Fibroblasts ◽  
Murine Gammaherpesvirus ◽  
Transformed Cell ◽  
Transformed Cell Lines ◽  
Nih 3T3

Human dermal fibroblasts and mouse NIH/3T3 cells acquired the transformed phenotype (‘criss-cross' pattern of growth) after infection with ultraviolet-irradiated murine gammaherpesvirus (MuHV-4 strain 68; MHV-68). These cells with changed phenotype could be serially cultured for 5-6 passages (35-40 days), and then they entered into crisis and most of them died. In a small number of cultures, however, foci of newly transformed cells appeared from which two stable cell lines were derived. After 6-9 cell culture passages of the MHV-68 transformed cell lines, MHV-68 DNA and virus antigen could be detected by PCR and immunofluorescence assay along with the disappearance of actin bundles, indicating that both transformed cell lines might be oncogenic.

A single point mutation in Drosophila dihydrofolate reductase confers methotrexate resistance to a transgenic CHO cell line

Genome ◽  
2003 ◽  
Vol 46 (4) ◽  
pp. 707-715 ◽  
Author(s):  
K Neumann ◽  
K M Al-Batayneh ◽  
M J Kuiper ◽  
J Parsons-Sheldrake ◽  
M G Tyshenko ◽  
...  
Keyword(s):  
Cell Line ◽  
Point Mutation ◽  
Cell Lines ◽  
Dihydrofolate Reductase ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Single Point Mutation ◽  
Parental Line ◽  
Wild Type ◽  
Drosophila Cell

Sequence analysis of a cDNA encoding dihydrofolate reductase (DHFR) from a selected methotrexate-resistant Drosophila melanogaster cell line (S3MTX) revealed a substitution of Gln for Leu at position 30. Although the S3MTX cells were ~1000 fold more resistant to methotrexate (MTX), the karyotype was similar to the parental line and did not show elongated chromosomes. Furthermore, kinetic analysis of the recombinant enzyme showed a decreased affinity for MTX by the mutant DHFR. To determine if the resistance phenotype could be attributed to the mutant allele, Drosophila Dhfr cDNAs isolated from wild type and S3MTX cells were expressed in Chinese hamster ovary (CHO) cells lacking endogenous DHFR. The heterologous insect DHFRs were functional in transgenic clonal cell lines, showing ~400-fold greater MTX resistance in the cell line transfected with the mutant Dhfr than the wild type Dhfr. Resistance to other antifolates in the CHO cells was consistent with the drug sensitivities seen in the respective Drosophila cell lines. ELevated Levels of Dhfr transcript and DHFR in transgenic CHO cells bearing the mutant cDNA were not seen. Taken together, these results demonstrate that a single substitution in Drosophila DHFR alone can confer Levels of MTX resistance comparable with that observed after considerable gene amplification in mammalian cells.Key words: dihydrofolate reductase, methotrexate, drug resistance, point mutation.

scholarly journals Loss of transcriptional activation of three sterol-regulated genes in mutant hamster cells.

1993 ◽  
Vol 13 (9) ◽  
pp. 5175-5185 ◽  
Author(s):  
M J Evans ◽  
J E Metherall
Keyword(s):  
Transcriptional Regulation ◽  
Cell Lines ◽  
Transcriptional Activation ◽  
Cho Cells ◽  
Mutant Cell ◽  
Chinese Hamster ◽  
Wild Type ◽  
Hmg Coa Reductase ◽  
Low Levels ◽  
Coa Reductase

Cholesterol biosynthesis and uptake are controlled by a classic end product-feedback mechanism whereby elevated cellular sterol levels suppress transcription of the genes encoding 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase, HMG-CoA reductase, and the low-density lipoprotein receptor. The 5'-flanking region of each gene contains a common cis-acting element, designated the sterol regulatory element (SRE), that is required for transcriptional regulation. In this report, we describe mutant Chinese hamster ovary (CHO) cell lines that lack SRE-dependent transcription. Mutant cell lines were isolated on the basis of their ability to survive treatment with amphotericin B, a polyene antibiotic that kills cells by interacting with cholesterol in the plasma membrane. Four mutant lines (SRD-6A, -B, -C, and -D) were found to be cholesterol auxotrophs and demonstrated constitutively low levels of mRNA for all three sterol-regulated genes even under conditions of sterol deprivation. The mutant cell lines were found to be genetically recessive, and all four lines belonged to the same complementation group. When transfected with a plasmid containing a sterol-regulated promoter fused to a bacterial reporter gene, SRD-6B cells demonstrated constitutively low levels of transcription, in contrast to wild-type CHO cells, which increased transcription under conditions of sterol deprivation. Mutation of the SREs in this plasmid prior to transfection reduced the level of expression in wild-type CHO cells deprived of sterols to the level of expression found in SRD-6B cells. The defect in SRD-6 cells is limited to transcriptional regulation, since posttranscriptional mechanisms of sterol-mediated regulation were intact: the cells retained the ability to posttranscriptionally suppress HMG-CoA reductase activity and to stimulate acyl-CoA:cholesterol acyltransferase activity. These results suggest that SRD-6 cells lack a factor required for SRE-dependent transcriptional activation. We contrast these cells with a previously isolated oxysterol-resistant cell line (SRD-2) that lacks a factor required for SRE-dependent transcriptional suppression and propose a model for the role of these genetically defined factors in sterol-mediated transcriptional regulation.

scholarly journals Establishment of fast-growing serum-free immortalised cells from Chinese hamster lung tissues for biopharmaceutical production

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Noriko Yamano-Adachi ◽  
Rintaro Arishima ◽  
Sukwattananipaat Puriwat ◽  
Takeshi Omasa
Keyword(s):  
Cell Line ◽  
Cho Cells ◽  
Mammalian Cells ◽  
High Efficiency ◽  
Chinese Hamster ◽  
Serum Free ◽  
Sterility Testing ◽  
Fast Growing ◽  
Defined Culture

Abstract Chinese hamster (Cricetulus griseus) ovary-derived Chinese hamster ovary (CHO) cells are the most commonly used mammalian hosts for the industrial production of recombinant therapeutics because of their ability to fold, assemble, and perform post-translational modifications, such as glycosylation, on proteins. They are also valuable for their ability to grow in serum-free suspension cultures. In this study, we established a cell line derived from lung tissue of Chinese hamsters, named Chinese hamster lung (CHL)-YN cells. The biosafety of CHL-YN cells was confirmed by in vitro sterility testing, mycoplasma detection, and reverse transcriptase assays. One of the key characteristics of CHL-YN cells was their doubling time of 8.1 h in chemically defined culture medium; thus, they proliferate much faster than conventional CHO cells and general mammalian cells. Transgenes could be introduced into CHL-YN cells with high efficiency. Finally, between 50% to > 100% of the amount of glycosylated immunoglobulin G (IgG)1 produced by CHO-K1 cells was produced by CHL-YN cells over a shorter period of time. In summary, fast-growing CHL-YN cells are a unique cell line for producing recombinant proteins.

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