Open AccessInduction of replicative DNA synthesis in quiescent human fibroblasts by DNA damaging agents.
Author(s) -
Steven M. Cohn,
Bruce R. Krawisz,
Steven L. Dresler,
Michael W. Lieberman
Publication year - 1984
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.81.15.4828
Subject(s) - semiconservative replication , xeroderma pigmentosum , dna synthesis , dna replication , microbiology and biotechnology , dna , biology , aphidicolin , bromodeoxyuridine , thymidine , fibroblast , wi 38 , dna repair , cell cycle , cell culture , cell division , dna damage , cell growth , cell , biochemistry , ploidy , eukaryotic dna replication , genetics , gene
A marked induction of DNA replication was observed in confluent human diploid fibroblast cultures treated with low relatively nontoxic doses of UV radiation, N-methyl-N-nitrosourea (MNU), and N-acetoxy-2-acetylaminofluorene (AAAF). Isopycnic CsCl density gradient analysis of newly synthesized DNA labeled with BrdUrd indicated that most of the synthesis was semiconservative. The rate of semiconservative DNA synthesis was maximal 24 hr after damage. This induction of DNA replication was greatest at approximately equal to 3 J/m2 UV, 0.5 mM MNU, or 1.0 microM AAAF; was inhibited by hydroxyurea and aphidicolin; and also occurred in repair-deficient xeroderma pigmentosum fibroblasts. Autoradiographic examination of both confluent cultures and serum-arrested cultures showed a large increase in the fraction of densely labeled (S phase) cells after UV treatment. These densely labeled cells retain the capacity for cell division and subsequent proliferation. We conclude that low doses of at least three different DNA damaging agents are capable of recruiting quiescent cells into a state of DNA replication similar to that observed in the normal cell cycle.