POLYMORPHISMS OF HUMAN AH RECEPTOR GENE ARE NOT INVOLVED IN LUNG-CANCER

The Ah receptor (Ahr) is a ligand-dependent transcription factor that positively regulates inducible expression of the CYP1A1 gene, Based on the sequence information of the human Ahr and the intron-exon junctio ns of the mouse counterpart, an analysis of single-strand conformation al polymorphism (SSCP) was carried out to detect subtle base differenc es in the coding region of the gene among individuals, We found that t he Ahr protein has at least two forms of variants in a Japanese gene p ool, and that these variants can be ascribed to one amino acid replace ment of Arg by Lys at codon 554, The frequencies of Arg-coded and Lys- coded alleles were 0.57 and 0.43, respectively, We found, however, tha t this germ line polymorphism of the Ahr gene did not show a significa nt association with aryl hydrocarbon hydroxylase (AHH) inducibility no r with lung cancer incidence.