Mouse embryo cell cultures

Pretazettine (395) has been the subject of numerous biological studies, and it has been shown to exhibit a number of interesting activities (96,97,101,178-187). For example, 395 was found to inhibit HeLa cell growth as well as protein synthesis in eukaryotic cells by interfering with the peptide bond formation step (97,101). Furthermore, pretazettine inhibited the purified RNA-dependent DNA polymerase (reverse transcriptase) from avian myeloblastosis virus, a typical C-type virus (178), in an unusual fashion since it physically combined with the polymerase enzyme itself rather than interacted with the nucleic acid template. Pretazettine also exhibited antiviral activity against the Rauscher leukemia virus in mouse embryo cell cultures by suppressing viral replication (179). 

To find whether the reduced foci formation was due to inhibition of MSV (M) replication, the effect of these compounds on virus growth was studied. Secondary mouse embryo cell cultures were infected with MSV (M) at the rate of 0.03 competent MSV infectious units per cell and treated with the compounds at different doses after the infection by the focus assay in the presence of an optimal amount of MLV (M) (1.01 10s Leukemia Vims Helper Units) according to Hirschman etal.33 Similarly treated uninfected cultures were trypsinized at the same time, and cells were counted. 

Fig. 10. Growth curve of MSV(M) in secondary mouse embryo cell cultures, untreated or treated with distamycin/5. The titers represent the total virus [yield at each day, determined with added excess helper virus]. Each day the cells were harvested in the supernatant and samples of this suspension were used for titration of MSV(M). Chandra efa/.27l...

Mondal, S., Brankov, D. W., and Heidelberger, C., Enhancement of oncogenesis in C3H/10T 1/2 mouse embryo cell cultures by saccharin. Science 201 1141-1143... 

C. 1978. Enhancement of Oncogenesis in C3H/10T /2 mouse embryo cell cultures by... 

Bischoff JR, Samuel CE (1985) Mechanism of interferon action. The interferon-induced phosphoprotein PI possesses a double-stranded RNA-dependent ATP-binding site. J Biol Chem 260 8237-8239 Bolovan CA, Sawtell NM, Thompson RL (1994) ICP34.5 mutants of herpes simplex virus type 1 strain 17syn+ are attenuated for neurovirulence in mice and for replication in confluent primary mouse embryo cell cultures. J Virol 68 48-55... 

Secondary cultures of hamster embryo cells metabolized 90% of the added DMBA in 48 hours. The major organic-soluble metabolite was the 8,9-dihydrodiol (19, 147). Hydroxymethyl derivatives were only minor metabolites. Glucuronides of DMBA phenols were also major metabolites. The results of this study suggest that there may be important differences between microsomal and whole cell metabolism of DMBA (19). Such differences were also evident when the products of binding of DMBA to DNA in mouse embryo cell cultures and mouse skin or catalyzed by Aroclor induced rat liver microsomes were compared. The major adducts observed in mouse skin or mouse embryo cell cultures resulted from metabolism in the 1-4 ring, presumably through the 3,4-dihydrodiol-1,2-epoxide, whereas the main adduct formed in the microsomal system resulted from reaction with the 4,5-epoxide of DMBA (35). 

Church, K. 1967. Pattern of DNA replication in binucleate cells occurring in mouse embryo cell cultures. Exp. Cell Res., 46 639-641. 

Miller, R. and Hall, E.J. (1978). "X-ray dose fractionation and oncogenic formations in cultured mouse embryo cells, Nature 272, 58. 

Identification of DNA-Reactive Metabolites Generated in a Target Tissue, Mouse Skin, In Vivo. Our initial studies focused on activation of DMBA in mouse embryo cells in culture because of the ease of isolation of sufficient DNA for adduct characterization. The cells were exposed to DMBA and the isolated DNA enzymatically hydrolyzed to deoxyribonucleosides. DMBA-deoxyribonucleoside adducts were characterized by fluorescence measurements (11,22), by photosensitivity studies (12) and by column chromatography (23,24). These studies provided evidence that the DNA-reactive metabolite generated in these cells is a bay region dihydrodiol epoxide. The enzymatic steps in this activation pathway (Figure 1) involve oxidation of DMBA by mixed function oxidases to a 3,4-epoxide which is converted by epoxide hydrase to a 3,4-dihydro-diol. This is, in turn, oxidized by mixed function oxidases to the dihydrodiol epoxide. 

In contrast, we did not find these concentration-dependent qualitative changes when activation occurred in intact cellular systems (16). We examined the adducts formed in mouse embryo cells in culture and in mouse skin ijri vivo over 40- and 100-fold DMBA concentration ranges, respectively, and found quantitative, but no qualitative, changes in binding (16). At all concentrations, activation appeared to be through the bay region dihydrodiol epoxide pathway. The cellular systems are physically very different from the homogenate systems and it is difficult to... 

Tor ado GJ Green H, (1963) Quantitative studies of the growth of mouse embryo cells in culture and their development into established lines. Journal of Cell Biology 17 299-313. 

Loo DT, Fuquay JI, Rawson CL Barnes DW (1987) Extended culture of mouse embryo cells without senescence inhibition by serum. Science 236 200-202. 

Fig. 9. Inhibition of MSV (M) replication and of cell proliferation by distamycin (0 ), distamycin/4 ( ) and distamycin/5 (a ). Empty symbols and continuous lines inhibition of MSV (M) production (titeration 3 days after infection). MSV (M) titer in untreated cultures ranged from 3.0x10s to 6.1x10s FFU/ml. Filled symbols and dotted lines inhibition of secondary mouse embryo cell proliferation. Cell number/plate in untreated cultures ranged from 1.1 x 10s to 2.6 x 10s. Chandra ef a/.27)...

Duncan ME, Brockers P. 1972. Metabolism and macromolecular binding of dibenz(a,/7)anthracene by mouse embryo cells in culture. Int J Cancer 9(2) 349-352. 

Hunter ES. 1998. Selenite prevents the dysmorphology and early phase cell cycle changes produced by arsenite in mouse embryos in culture [Abstract], Teratology 57(4/5) 215-216. 

Nordenskjold, B. A., L. Skoog, N. C. Brown, and P. Reichard. 1970. Deoxyribonucleotide pools and deoxyribonucleic acid synthesis in cultured mouse embryo cells. J. Biol. Chem., 245 5360-5368. 

The nucleotide patterns of cultured animal cells and ascites tumor cells are generally less vulnerable than those of tissues however, if washing is required, a medium capable of supporting energy metabolism should be employed. If cells are to be packed by centrifugation prior to extraction, cultures or ascitic fluids may first have to be cooled. Cells are extracted in the cold some procedures employ alternate freezing and thawing in the presence of acidic extractants. Extraction of cultured mouse embryo cells with 60% methanol for 16 hours at — 20 C has been employed in the analysis of deoxyribonucleoside triphosphates 9). 

The nucleotide pools of chick fibroblasts proliferating exponentially in culture have been determined by an isotopic method as seen in Table l-III, in these cells the pool of ATP is about 10 times that of any other ribonucleoside triphosphate and more than 100 times that of dATP or dTTP (14)- The small size of the deoxyribonucleotide pool in the exponentially proliferating cells is consistent with observations by others and suggests that the deoxyribonucleotides are synthesized as needed for DNA synthesis and do not accumulate. Skoog and Nordenskjold (5) have estimated that in cultures of mouse embryo cells undergoing DNA synthesis, the pool of dGTP was sufficient to support only about 30 seconds of DNA... 

Orlova, T. G., Orlova, N. G., and Eremkina, E. I., 1%9, Sialidase activity of chick and mouse embryo tissue culture cells infected with myxoviruses and the effect of actinomycin D on this activity, Acta Virol. 13 363-370. 

Evans MJ, Kaufman MH (1981) Establishment in culture of pluripotential cells from mouse embryos. Nature 292 154—156... 

Such cells are often classified on the basis of their original source as either embryonic or adult stem cells. As the name suggests, embryonic stem cells are derived from the early embryo, whereas adult stem cells are present in various tissues of the adult species. Much of the earlier work on embryonic stem cells was conducted using mouse embryos. Human embryonic stem cells were first isolated and cultured in the laboratory in 1998. Research on adult stem cells spans some four decades, with the discovery during the 1960s of haematopoietic stem cells in the bone marrow (Chapter 10). However, the exact distribution profile, role and ability to manipulate adult stem cells (particularly those outside of the bone marrow) are subjects of intense current research, and for which more questions remain than are answered. 

The concentration of toxin which causes a 50% reduction in cell bound dye after five days in culture. Cell lines used were H4TG, thioguanine-resistant rat hepatoma cells MDCK, Madin-Darb and canine kidney cells NIH3T3,NIH Swiss mouse embryo fibroblasts and KA31T, Kirsten strain of Moloney sarcoma virus-transformed 3T3 cells. 

Unscheduled DNA synthesis was not induced in either mouse or hirman primary hepatocyte cultures with mono(2-ethylhexyl) phthalate, and neither this metabolite nor 2-ethylhexanol induced mutations in mouse lymphoma cells in vitro. Mono(2-ethyl-hexyl) phthalate induced sister-chromatid exchange in Chinese hamster V79 cells and chromosomal aberrations in Syrian hamster embryo cells. It also induced transformation in Syrian hamster embryo cells, but not in mouse C3H10T /2 cells. Gap-junctional intercellular communication was inhibited by mono(2-ethylhexyl) phthalate in Syrian hamster embryo cells and in Chinese hamster V79 cells. As reported in an abstract (Baker et al., 1996), this function was also inhibited in rat and mouse hepatocytes, but not in Syrian hamster or human hepatocytes. 

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