Detection of Carcinogen-DNA Adducts in Human Fetal Tissues by the 32 P-Postlabeling Procedure

Abstract

Tobacco smoke contains a number of genotoxic compounds that are metabolized to their biologically active forms that subsequently react with cellular DNA to form covalently boundcarcinogen-DNA adducts. Several analytical procedures have been developed to detect these adducts in human tissues. Using the nuclease P1-enhanced 32P-postlabeling procedure for bulky adducts, we have detected at least 24 adducts in DNA isolated from placenta and umbilical cord DNA. Adducts were detected in both smokers and nonsmokers, but the relative adduct level (RAL) was significantly higher in smokers (42. 8, 8 cases) than in nonsmokers (19.7, 11 cases). The origin of the adducts in nonsmokers remains unknown. The adduct levels in artery DNA were significantly lower than in the vein and the placenta, and a paired nonparametric analysis showed a significant association between the adduct levels in the three tissues. Our results show a maternal transfer of carcinogens present in cigarette smoke to fetal tissues and show that the tissues can metabolize the carcinogens to their DNA binding metabolites. The presence of adducts in fetal tissues may be indicative of genomic damage and may predispose the individual for the development of a serious disease iter in life.

In Utero Exposure to Benzo[a]pyrene Induces Ovarian Mutations at Doses That Deplete Ovarian Follicles in Mice

“…Exposure of pregnant rats to BaP via oral or inhalation routes results in BaP-dosedependent concentrations of BaP metabolites in blood and tissues of offspring on the day of birth, with levels declining over the subsequent postnatal weeks (Wu et al 2003;Jules et al 2012). Smoking-related DNA and albumin adducts, including BaP-specific adducts, have been detected in human fetal tissues (Hansen et al 1993;Autrup and Vestergaard 1996). Humans are exposed to dozens of mutagenic PAHs in addition to BaP.…”

Biomonitoring the human population exposed to pollution from the oil fires in Kuwait: Analysis of placental tissue using32P-postlabeling

“…There are a growing number of studies that show a relationship between DNA adduct levels in placenta, exposure to environmental PAHs or tobacco smoke, and activity of cytochrome p450s [Everson et al, 1986[Everson et al, , 1987Hansen et al, 1993;Topinka et al, 1997;Whyatt et al, 1998a,b;Lagueux et al, 1999]. One possibility is that the control subjects who provided placenta 12 months after the oil fires were exposed to PAHs other than through airborne pollution, which might include sources such as contamination of food or drinking water.…”

“…A number of studies have demonstrated the presence of smoking-related DNA adducts in placenta [Everson et al, 1986, Hansen et al, 1993Topinka et al, 1997] and elevations of DNA adducts associated with smoking have been reported for a variety of tissues, including lung, kidney, bladder, esophagus, and oral tissues [Phillips et al, 1988b;Randerath et al, 1989;Cuzick et al, 1990;Jones et al, 1993]. As expected, adduct levels were found to be lower in the placental samples from nonsmoking mothers, in which the mean values were roughly half those seen in smoking mothers for both enhancement techniques (Table II).…”

“…Nevertheless, mean adduct levels were found to be higher in the 30 UK smoking mothers than in the 12 UK nonsmoking mothers. Also, it should be remembered that the purpose of examining UK mothers in this study was to provide a comparison for Kuwaiti samples and not to equivocally determine a link between smoking and adduct levels in placenta, as this has been adequately demonstrated in a number of previous studies [Everson et al, 1986[Everson et al, , 1987Hansen et al, 1993;Topinka et al, 1997;Whyatt et al, 1998a,b;Lagueux et al, 1999]. Interestingly, examination of the adduct profiles on the chromatograms of the UK samples did appear to reveal a number of adduct spots that seemed to be exclusively associated with cigarette smoking.…”

“…An increase in PAH-DNA adducts in the lymphocytes of foundry workers correlated with increasing exposure to PAHs, and adducts associated with tobacco smoking have been detected in a variety of tissues, including lung and oral tissue, using PPL [Phillips et al, 1988a,b;Jones et al, 1993]. A number of reports demonstrated the presence of DNA adducts in human placenta that were associated with maternal smoking during pregnancy, again using PPL [Everson et al, 1986[Everson et al, , 1987Hansen et al, 1993].…”