title: Immortalisation of a human diploid fibroblast cell strain: a DT-diaphorase paradox.
abstract: Transfection of a normal human diploid fibroblast cell strain, GM38, with a simian virus 40 (SV40) large T antigen containing plasmid, yielded an immortal cell line, G38-8X, which had a similar sensitivity as the parental cell strain to the quinone-containing chemotherapeutic agent mitomycin C (MMC), under both aerobic and hypoxic exposure conditions. The activity level of DT-diaphorase was similar in both the parental GM38 and G38-8X cells. Although DT-diaphorase could be detected by Western blot analysis, using two mouse anti-human monoclonal antibodies, in GM38 cells, it was not detected in the G38-8X cells. G38-8X cells have a slightly increased P450R activity (2-fold), and have elevated P-glycoprotein levels compared with the parental GM38 cell strain. The immortal G38-8X cell line is 2-fold more resistant to ionising radiation than the parental GM38 cell strain (D10 approximately 5 Gy). Although these SV40 large T antigen immortalised human diploid fibroblasts behaved similarly to their parental cell strain in terms of MMC sensitivity and DT-diaphorase activity, careful characterisation revealed that these cells had enhanced P-glycoprotein activity and had a decreased sensitivity to ionising radiation.
authors.affiliation: Department of Medical Biophysics, University of Toronto, Ontario, Canada.
authors.forename: B L
authors.initials: BL
authors.lastname: Kuehl
authors.forename: C B
authors.initials: CB
authors.lastname: Brezden
authors.forename: R D
authors.initials: RD
authors.lastname: Traver
authors.forename: D
authors.initials: D
authors.lastname: Siegel
authors.forename: D
authors.initials: D
authors.lastname: Ross
authors.forename: J
authors.initials: J
authors.lastname: Renzing
authors.forename: A M
authors.initials: AM
authors.lastname: Rauth
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D051379:Mice; D016685:Mitomycin / Q000494:pharmacology*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D011836:Radiation Tolerance; D014162:Transfection
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D000952:Antigens, Polyomavirus Transforming; D016685:Mitomycin; D009251:NADPH-Ferrihemoprotein Reductase; D016660:NAD(P)H Dehydrogenase (Quinone)