Similarities between human ataxia fibroblasts and murine SCID cells: High sensitivity to γ rays and high frequency of methotrexate-induced DHFR gene amplification, but normal radiosensitivity to densely ionizing α particles
Tóm tắt
Twoγ-ray hypersensitive cell lines, human ataxia telangiectasia (AT) and murine severe combined immune deficiency (SCID) cells, proved to be very competent in amplifying their dihydrofolate reductase (DHFR) gene under methotrexate selection stress. Over a period of months, methotrexate-resistant clones were obtained which were able to grow in progressively increasing methotrexate concentrations up to 1 mM. By then methotrexate-resistant AT and SCID cells had amplified their DHFR gene 6- and 30-fold, respectively, and showed very high DHFR mRNA expression. In contrast, related cells with normal radiosensitivity (human GM637 and mouse BALB/c fibroblasts) did not show DHFR gene amplification under comparable conditions. This correlation of the capacity of DHFR gene amplification andγ-ray hypersensitivity in AT and SCID cells suggests that gene amplification may have a mechanism(s) in common with those involved in repair ofγ-radiation-induced damage. No difference in cell killing could be observed following exposure to densely ionizing α particles: AT and SCID cells exhibited comparable survival rates to GM637 and BALB/c cells, respectively.
Tài liệu tham khảo
Anagnou NP, O' Brien SJ, Shimada T, Nash WG, Chen MJ, Nienhuis AW (1984) Chromosomal organisation of the human dihydrofolate reductase genes: dispersion, selective amplification and a novel form of polymorphism. Proc Natl Acad Sci USA 81:5170–5174
Biedermann KA, Sun J, Giaccia AJ, Tosto LM, Brown JM (1991) Scid mutation in mice confers hypersensitivity to ionizing radiation and a deficiency in DNA double-strand break repair. Proc Natl Acad Sci USA 88:1394–1397
Blöcher D, Sigut D, Hannan MA (1991) Fibroblasts from ataxia telangiectasia (AT) and AT heterozygotes show an enhanced level of residual DNA double-strand breaks after low dose-rateγ-irradiation as assayed by pulsed field gel electrophoresis. Int J Radiat Biol 60:791–802
Bosma GC, Custer RP, Bosma MJ (1983) A severe combined immunodeficiency mutation in the mouse. Nature 301:527–530
Budach W, Hartford A, Gioioso D, Freeman J, Taghian A, Suit HD (1992) Tumors arising in SCID mice share enhanced radiation sensitivity of SCID normal tissues. Cancer Res 52:6292–6296
Carbonari M, Cherchi M, Paganelli R, Giannini G, Galli E, Gaetano C, Papetti C, Fiorilli M (1990) Relative increase of T cells expressing the gamma/delta rather than the alpha/beta receptor in ataxia-telangiectasia. N Engl J Med 322:73–76
Chadwick KH, Leenhouts HP (1981) The molecular theory of radiation biology. Springer, Berlin Heidelberg New York
Coquerelle TM, Weibezahn KF, Lücke-Huhle C (1987) Rejoining of double strand breaks in normal human and ataxia-telangiectasia fibroblasts after exposure to 60Coγ-rays, 241 AM α-particles or bleomycin. Int J Radiat Biol 51:209–218
Fulop GM, Phillips RA (1990) The scid mutation in mice causes a general defect in DNA repair. Nature 347:479–482
Gasser CS, Simonsen CC, Schilling JW, Schimke RT (1982) Expression of abbreviated mouse dihydrofolate reductase genes in cultured hamster cells. Proc Natl Acad Sci USA 79:6522–6526
Giulotto E, Bertoni L, Attolini C, Rainaldi G, Anglana M (1991) BHK cell lines with increased rates of gene amplification are hypersensitive to ultraviolet light. Proc Natl Acad Sci USA 88:3484–3488
Hendrickson EA, Qin X-Q, Bump EA, Schatz DG, Oettinger M, Weaver DT (1991) A link between double-strand break-related repair and V(D)J recombination: the scid mutation. Proc Natl Acad Sci USA 88:4061–4065
Hinrichs S (1986) Methotrexat Resistenz durch Genamplifikation in menschlichen Hautfibroblasten. Diplomarbeit, Universität Karlsruhe
Itoh M, Hamatani K, Komatsu K, Araki R, Takayama K, Abe M (1993) Human chromosome 8 (p12 → q22) complements radiosensitivity in the severe combined immune deficiency (SCID) mouse. Radiat Res 134:364–368
Komatsu K, Yoshida M, Okumura Y (1993) Murine scid cells complement ataxia-telangiectasia cells and show a normal post-irradiation response of DNA synthesis. Int J Radiat Biol 63:725–730
Lavi S, Etkin S (1981) Carcinogen-mediated induction of SV40 DNA snythesis in SV40 transformed Chinese hamster embryo cells. Carcinogenesis 2:417–423
Lücke-Huhle C, Comper W, Hieber L, Pech M (1982) Comparative study of G2 delay and survival after241 Americium-α and60Cobalt-γ irradiation. Radiat Environ Biophys 20:171–185
Lücke-Huhle C, Hinrichs S, Speit G (1987) DHFR gene amplification in cultured skin fibroblasts of ataxia telangiectasia patients after methotrexate selection. Carcinogenesis 8:1801–1806
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning. A laboratory manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY
Meyn MS (1993) High spontaneous intrachromosomal recombination rates in ataxia-telangiectasia. Science 260:1327–1330
Minty AJ, Caravatti M, Robert B, Cohen A, Daubas P, Weydert A, Gros F, Buckingham ME (1981) Mouse actin messenger RNAs. J Biol Chem 256:1008–1014
Painter RB, Young BR (1980) Radiosensitivity in ataxia-telangiectasia: a new explanation. Proc Natl Acad Sci USA 77:7315–7317
Powell S, Whitaker S, Peacock J, McMillan T (1993) Ataxia telangiectasia: an investigation of the repair defect in the cell line AT5BIVA by plasmid reconstitution. Mutat Res 294:9–20
Rigby PWJ, Dieckmann M, Rhodes C, Berg P (1977) Labeling deoxyribonucleic acid to high specific activity in vitro by nick translation with DNA polymerase. J Mol Biol 113:237–251
Ritter S, Kraft-Weyrather W, Scholz M, Kraft G (1992) Induction of chromosome aberrations in mammalian cells after heavy ion exposure. Adv Space Res 12:119–125
Southern EM (1975) Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol 98:503–517
Tlsty TD (1990) Normal diploid human and rodent cells lack a detectable frequency of gene amplification. Proc Natl Acad Sci USA 87:3132–3136
Wright JA, Smith HS, Watt FM, Hancock MC, Hudson DL, Stark GR (1990) DNA amplification is rare in normal human cells. Proc Natl Acad Sci USA 87:1791–1795