TY - JOUR
T1 - Methylation of deoxycytidine in replicating cells treated with ultraviolet radiation and chemical carcinogens
AU - Krawisz, Bruce R.
AU - Lieberman, Michael W.
N1 - Funding Information:
We thank Steven Conn, Michael Kastan, Frederick Barr, Steven Dresler, Russell Lebovitz and Thomas Winokur for their thoughtful comments and Ms. Renay Walker for her excellent secretarial assistance. This work was supported by N1H Grant CA-31734 and the following companies: Brown and Williamson Tobacco Corporation, Philip Morris Incorporated, R.J. Reynolds Tobacco Company and the United States Tobacco Company. Bruce Krawisz was a feflow of the Tumor Biology Training Program 5 T32 CA09118-09.
Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 1984/9
Y1 - 1984/9
N2 - 5-Methyl-2'-deoxycytidine (m5dC) levels were measured in DNA from three types of cultured cells following treatment with u.v. radiation and two chemical carcinogens, N-methyl-N-nitrosourea (MNU) and N-acetoxy-2-acetylaminofluorene (NA-AAF). Control values for m5dC in Raji cells (a human lymphoblastoid cell line), S49 cells (a mouse thymic lymphoma cell line) and human diploid fibroblasts are 3.6%, 3.6% and 3.2%, respectively. None of the damaging agents produced a detectable change in methylation levels of newly replicated DNA, even at levels of damage that inhibited replication by 95%. In contrast, treatment with 5-aza-2'-deoxycytidine, a known methyltransferase inhibitor, transiently reduced genomic methylation by 89% and 74% in Raji and S49 cells, respectively. Although other investigators have found a marked reduction in m5dC in DNA replicated after carcinogen treatment, our experiments indicate that extensive demethylation is not a necessary consequence of DNA damage.
AB - 5-Methyl-2'-deoxycytidine (m5dC) levels were measured in DNA from three types of cultured cells following treatment with u.v. radiation and two chemical carcinogens, N-methyl-N-nitrosourea (MNU) and N-acetoxy-2-acetylaminofluorene (NA-AAF). Control values for m5dC in Raji cells (a human lymphoblastoid cell line), S49 cells (a mouse thymic lymphoma cell line) and human diploid fibroblasts are 3.6%, 3.6% and 3.2%, respectively. None of the damaging agents produced a detectable change in methylation levels of newly replicated DNA, even at levels of damage that inhibited replication by 95%. In contrast, treatment with 5-aza-2'-deoxycytidine, a known methyltransferase inhibitor, transiently reduced genomic methylation by 89% and 74% in Raji and S49 cells, respectively. Although other investigators have found a marked reduction in m5dC in DNA replicated after carcinogen treatment, our experiments indicate that extensive demethylation is not a necessary consequence of DNA damage.
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U2 - 10.1093/carcin/5.9.1141
DO - 10.1093/carcin/5.9.1141
M3 - Article
C2 - 6467503
AN - SCOPUS:0021210692
VL - 5
SP - 1141
EP - 1144
JO - Carcinogenesis
JF - Carcinogenesis
SN - 0143-3334
IS - 9
ER -