title: In utero exposure of mice to dibenzo[a,l]pyrene produces lymphoma in the offspring: role of the aryl hydrocarbon receptor.
abstract: Lymphoma and leukemia are the most common cancers in children and young adults; in utero carcinogen exposure may contribute to the etiology of these cancers. A polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP), was given to pregnant mice (15 mg/kg body weight, gavage) on gestation day 17. Significant mortalities in offspring, beginning at 12 weeks of age, were observed due to an aggressive T-cell lymphoblastic lymphoma. Lymphocytes invaded numerous tissues. All mice surviving 10 months, exposed in utero to DBP, exhibited lung tumors; some mice also had liver tumors. To assess the role of the aryl hydrocarbon receptor (AHR) in DBP transplacental cancer, B6129SF1/J (AHR(b-1/d), responsive) mice were crossed with strain 129S1/SvIm (AHR(d/d), nonresponsive) to determine the effect of maternal and fetal AHR status on carcinogenesis. Offspring born to nonresponsive mothers had greater susceptibility to lymphoma, irrespective of offspring phenotype. However, when the mother was responsive, an AHR-responsive phenotype in offspring increased mortality by 2-fold. In DBP-induced lymphomas, no evidence was found for TP53, beta-catenin, or Ki-ras mutations but lung adenomas of mice surviving to 10 months of age had mutations in Ki-ras codons 12 and 13. Lung adenomas exhibited a 50% decrease and a 35-fold increase in expression of Rb and p19/ARF mRNA, respectively. This is the first demonstration that transplacental exposure to an environmental PAH can induce a highly aggressive lymphoma in mice and raises the possibility that PAH exposures to pregnant women could contribute to similar cancers in children and young adults.
authors.affiliation: Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331-7301, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yu
authors.forename: Christiane V
authors.initials: CV
authors.lastname: Loehr
authors.forename: Kay A
authors.initials: KA
authors.lastname: Fischer
authors.forename: Mandy A
authors.initials: MA
authors.lastname: Louderback
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Krueger
authors.forename: Roderick H
authors.initials: RH
authors.lastname: Dashwood
authors.forename: Nancy I
authors.initials: NI
authors.lastname: Kerkvliet
authors.forename: Clifford B
authors.initials: CB
authors.lastname: Pereira
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Jennings-Gee
authors.forename: Stephanie T
authors.initials: ST
authors.lastname: Dance
authors.forename: Mark Steven
authors.initials: MS
authors.lastname: Miller
authors.forename: George S
authors.initials: GS
authors.lastname: Bailey
authors.forename: David E
authors.initials: DE
authors.lastname: Williams
mesh_terms: D000818:Animals; D001580:Benzopyrenes / Q000493:pharmacokinetics / Q000494:pharmacology / Q000633:toxicity*; D002273:Carcinogens / Q000493:pharmacokinetics / Q000494:pharmacology / Q000633:toxicity*; D004252:DNA Mutational Analysis; D005260:Female; D007150:Immunohistochemistry; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000139:chemically induced*; D008113:Liver Neoplasms / Q000139:chemically induced; D008175:Lung Neoplasms / Q000139:chemically induced; D008297:Male; D051379:Mice; D010641:Phenotype; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000502:physiology; D013534:Survival; D013953:Thymus Neoplasms / Q000139:chemically induced*
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D018336:Receptors, Aryl Hydrocarbon; C041517:dibenzo(a,l)pyrene