• The absence of interaction between drug metabolizing enzyme genotypes and maternal lifestyle factors on glycophorin A somatic mutation frequency levels in newborns.

      Nukui, Tomoko; Day, Richard D.; Gordish-Dressman, Heather A.; Harger, Gail; Bigbee, William L.; Ness, Roberta B.; Romkes, Marjorie (2006-02)
      Prenatal exposure to carcinogens results in newborn DNA damage which in turn is associated with impaired health conditions in both childhood and adulthood. The present study aimed to evaluate whether phase I and II biotransformation enzyme genetic polymorphisms in combination with environmental exposures during pregnancy result in elevated levels of newborn DNA damage. Maternal peripheral and umbilical cord blood samples from 406 mother/newborn pairs were genotyped for a panel of phase I/II metabolic enzymes (CYP1A1, CYP2E1, GSTM1, GSTT1 and NAT2) responsible for the metabolism of tobacco and lifestyle-related mutagens and carcinogens. DNA damage was measured by somatic cell mutation frequency at the glycophorin A (GPA) locus in newborns. No association with elevated somatic cell mutation frequency was observed between the combination of maternal/newborn genotypes and cigarette smoke or lifestyle exposures. The observed variation in newborn GPA frequency might be due to either environmental factors not assessed in this study or inter-individual differences in alternative metabolic or DNA repair pathways.
    • Indole-3-carbinol in the maternal diet provides chemoprotection for the fetus against transplacental carcinogenesis by the polycyclic aromatic hydrocarbon dibenzo[a,l]pyrene.

      Yu, Zhen; Mahadevan, Brinda; Lohr, Christiane V.; Fischer, Kay A.; Louderback, Mandy A.; Krueger, Sharon K.; Pereira, Clifford B.; Albershardt, Daniel J.; Baird, William M.; Bailey, George S.; et al. (2006-10)
      The fetus and neonate are sensitive targets for chemically induced carcinogenesis. Few studies have examined the risk/benefit of chemoprotective phytochemicals, given in the maternal diet, against transplacental carcinogenesis. In this study, B6129 SF1/J (AHR(b-1/d)) and 129Sv/ImJ (AHR(d/d)) mice were cross-bred. The polycyclic aromatic hydrocarbon, dibenzo[a,l]pyrene (DBP), was administered to pregnant mice (15 mg/kg, gavage) on gestation day 17, and 2000 p.p.m. indole-3-carbinol (I3C), a chemoprotective phytochemical from cruciferous vegetables, was fed to half of the mice from gestation day 9 until weaning. Offspring born to dams fed I3C exhibited markedly fewer mortalities (P < 0.0001). Maternal dietary exposure to I3C also significantly lowered lung tumor multiplicity (P = 0.035) in offspring surviving to 10 months of age. The I3C chemoprotection was independent of either maternal or fetal AHR genotype. The bioavailability of DBP to fetal target tissue was demonstrated by assessing DNA covalent adduction with a (33)P-post-labeling assay. The bioavailability of I3C was determined by dosing a subset of pregnant mice with [(14)C]-I3C. Addition of chemoprotective agents to the maternal diet during pregnancy and nursing may be an effective new approach in reducing the incidence of cancers in children and young adults.