Biopolym. Cell. 1987; 3(2):88-95.
Gene-Engineering Biotechnology
Amplification of dihydrofolate reductase genes and their transfer to animal cells
1Kuznetsova N. N., 1Mukhatnedkhanova F. S., 1Nuridzhanyants S. S., 1Abdukarimov A. A., 1Sadykov A. S.
  1. Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR
    Tashkent, USSR

Abstract

A new subline of Chinese hamster cells BFFR3, derived from fibroblast-like cell line Blld-ii-FAF28 (431 clone), and resistant to 132 (μg/ml of metotrexate(mtx) has been described. Karyotype study has revealed the specific changes in resistant cells in the form of homogeneously stained within chromosomes 2 and 5, and at the same time single double minute chromosomes being amplified dihydrofolate reductase genes. Variation in the modal class of resistant cells is found in the process of selection, the cells with 24 chromosomes (40 %) being dominated. The transfer of drug resistance has been performed while treating mtx-sensitive FStk~ cells with DNA, isolated from resistant BFFB3 cells and the formation of colonies with low frequency (1.04-10~6) has been shown. Thus, the amplification of target-genes under action of mtx underlies variability of cell population.

References

[1] Biedler JL, Spengler BA. Quantitative relationship between a chromosome abnormality (HSP) and antifolate resistance associated with enzyme overproduction. J Cell Biol. 1976; 70(2):117a.
[2] Massino IuS, Kakpakova ES, Kopnin BP, Pogosiants EE. Relation of mammalian cell resistance to actinomycin D with a change in the karyotype and a decrease in cytoplasmic membrane permeability. Genetika. 1981;17(7):1253-8.
[3] Suttle DP, Stark GR. Coordinate overproduction of orotate phosphoribosyltransferase and orotidine-5'-phosphate decarboxylase in hamster cells resistant to pyrazofurin and 6-azauridine. J Biol Chem. 1979;254(11):4602-7.
[4] Lewis WH, Kuzik BA, Wright JA. Assay of ribonucleotide reduction in nucleotide-permeable hamster cells. J Cell Physiol. 1978;94(3):287-98.
[5] Mamont PS, Duchesne MC, Grove J, Tardif C. Initial characterization of a HTC cell variant partially resistant to the anti-proliferative effect of ornithine decarboxylase inhibitors. Exp Cell Res. 1978;115(2):387-93.
[6] Nunberg JH, Kaufman RJ, Schimke RT, Urlaub G, Chasin LA. Amplified dihydrofolate reductase genes are localized to a homogeneously staining region of a single chromosome in a methotrexate-resistant Chinese hamster ovary cell line. Proc Natl Acad Sci U S A. 1978;75(11):5553-6.
[7] Kaufman RJ, Brown PC, Schimke RT. Amplified dihydrofolate reductase genes in unstably methotrexate-resistant cells are associated with double minute chromosomes. Proc Natl Acad Sci U S A. 1979;76(11):5669-73.
[8] Kopnin BP, Gudkov AV. Amplification of genome regions in the somatic cells of mammals resistant to colchicine. III. Localization of the amplified genes in minute chromatin bodies. Genetika. 1982;18(10):1683-92.
[9] Simonsen CC, Brown PC, Crouse GF et al. Gene amplification as a mechanism for drug resistance in cultured animal cells. Mol . basis drug action, proc. int. symp. (Queretaro, Oct. 13-16, 1980). New York, 1981:343-359.
[10] Yerganian G, Leonard MJ. Maintenance of normal in situ chromosomal features in long-term tissue cultures. Science. 1961;133(3464):1600-1.
[11] Zakharov AF, Kakpakova ES, Egolina NA, Pogosianz HE. Chromosomal variability in clonal populations of a Chinese hamster cell strain. J Natl Cancer Inst. 1964;33:935-56.
[12] Deaven LL, Petersen DF. The chromosomes of CHO, an aneuploid Chinese hamster cell line: G-band, C-band, and autoradiographic analyses. Chromosoma. 1973;41(2):129-44.
[13] Kuznetsova NN, Mukhamedkhanova FS, Nuridzhanyants SS, Leont'yev VB. New methotrexate-resistant cell line of Chinese hamster. Dokl akad nauk Uzbekskoy SSR. 1983; II:52-3.
[14] Kao FT, Puck TT. Genetics of somatic mammalian cells. IX. Quantitation of mutagenesis by physical and chemical agents. J Cell Physiol. 1969;74(3):245-58.
[15] Graham FL, van der Eb AJ. A new technique for the assay of infectivity of human adenovirus 5 DNA. Virology. 1973;52(2):456-67.
[16] van der Eb AJ, Graham FL. Assay of transforming activity of tumor virus DNA. Methods Enzymol. 1980;65(1):826-39.
[17] Pellicer A, Wigler M, Axel R, Silverstein S. The transfer and stable integration of the HSV thymidine kinase gene into mouse cells. Cell. 1978;14(1):133-41.
[18] Kopnin BP. Specific karyotype changes in cells resistant to colchicine. Genetika. 1981;17(2):308-17.
[19] Kopnin BP, Gudkov AV. Amplification of portions of the genome in the somatic cells of mammals resistant to colchicine. IV. Genetic transformation using amplified genes from Djungarian hamster cells highly resistant to colchicine. Genetika. 1983;19(6):864-71.