Molecular analysis of the CYP2F1 gene: identification of a frequent non-functional allelic variant.
The CYP2F1 is a human cytochrome P450 that is selectively expressed in lung tissue and involved in the metabolism of various pneumotoxicants with potential carcinogenic effects. In the present study, we report the first systematic investigation of the genetic polymorphism of this enzyme. We analyzed the nucleotidic sequence of the CYP2F1 gene in DNA samples from 90 French Caucasians consisting in 44 patients with lung cancer and 46 control individuals, using single-strand conformation polymorphism analysis of PCR products (PCR-SSCP). We identified 24 novel mutations distributed in the promoter region of the gene, as well as in the coding regions and their flanking intronic sequences. In addition to the wild-type CYP2F1*1 allele, seven allelic variant, CYP2F1*2A, *2B, *3, *4, *5A, *5B and *6, were characterized. The most frequent allelic variant, CYP2F1*2A (25.6%), harbors a combination of 9 mutations, including 2 missense mutations (Asp218Asn and Gln266His) and a 1-bp insertion (c.14_15insC) that creates a premature stop codon in exon 2, probably leading to the synthesis of a severely truncated protein with no catalytic activity. The identification of around 7% of homozygotes for the frameshift mutation in our Caucasian population suggests the existence of an interindividual variation of the CYP2F1 activity and, consequently, the possibility of interindividual differences in the toxic response to some pneumotoxicants and in the susceptibility to certain chemically induced diseases. However, our preliminary results did not show any evidence that the CYP2F1 genetic polymorphism has implications in the pathogenesis of lung cancer.
Tournel
Gilles
G
Equipe d'accueil 2679, Faculté de Médecine de Lille, Pôle Recherche, Lille, France. gills.tournel@univ-lille2.fr
Cauffiez
Christelle
C
Billaut-Laden
Ingrid
I
Allorge
Delphine
D
Chevalier
Dany
D
Bonnifet
Fabien
F
Mensier
Eric
E
Lafitte
Jean-Jacques
JJ
Lhermitte
Michel
M
Broly
Franck
F
Lo-Guidice
Jean-Marc
JM
D000483:Alleles; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D000072467:Cytochrome P450 Family 2; D004252:DNA Mutational Analysis; D017931:DNA Primers; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000235:genetics*; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D018807:Polymorphism, Single-Stranded Conformational; D017384:Sequence Deletion
D017931:DNA Primers; D003577:Cytochrome P-450 Enzyme System; C110332:CYP2F1 protein, human; D000072467:Cytochrome P450 Family 2