title: Correlation of inducibility of aryl hydrocarbon hydroxylase with susceptibility to 3-methylcholanthrene-induced lung cancers.
abstract: C57BL/6Cum, DBA/2Cum, first filia (F1), and backcross progeny from these 2 parental strains of mice were evaluated for their susceptibility to 3-methylcholanthrene-induced lung cancers. In the crosses among these mice, aryl hydrocarbon hydroxylase (AHH) responsiveness segregated as a single autosomal dominant gene (the Ah locus). AHH responsive mice (Ahb allele) expressed 40-60 units AHH activity/g wet wt liver following intraperitoneal treatment with 3-methylcholanthrene (MCA) compared to AHH non-responsive mice (Ahd allele) which expressed 7-11 units AHH activity/g wet wt liver after MCA treatment. Intratracheal administration of 500 microgram MCA for a total of 4 times at weekly intervals yielded a variety of pulmonary cancers, including squamous cell carcinomas, alveolar adenocarcinomas, and adeno-squamous cell carcinomas among mice that survived 1 year after the carcinogen treatment. The AHH responsive C57BL/6Cum, F1, and C57BL/6Cum X F1 animals were much more susceptible to MCA-induced lung cancers than the AHH non-responsive DBA/2Cum mice. The lung cancers were also not randomly distributed in DBA/2Cum X F1 backcross progeny since significantly more lung cancers were found in AHH-responsive progeny than in AHH non-responsive mice. Data support genetic linkage between susceptibility to MCA-induced lung carcinomas and the Ahb allele.
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis*; D001711:Biotransformation; D004790:Enzyme Induction; D005260:Female; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000235:genetics / Q000473:pathology; D008297:Male; D008748:Methylcholanthrene / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics; D013997:Time Factors
chemical_list: D008748:Methylcholanthrene; D001189:Aryl Hydrocarbon Hydroxylases