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Acetaldehyde‐induced mutation at the hprt Locus in Human Lymphocytes In Vitro
Author(s) -
He SaiMei,
Lambert Bo,
McCormick J. J.
Publication year - 1990
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.2850160202
Subject(s) - hypoxanthine guanine phosphoribosyltransferase , microbiology and biotechnology , mutant , biology , sister chromatid exchange , mutation frequency , hypoxanthine , mutagen , gene , genetics , dna , biochemistry , enzyme
Acetaldehyde (Aa) induces chromosomal aberration and sister chromatid exchange in a variety of test systems, but has not previously been evaluated for its ability to induce gene mutation in mammalian cells. We have studied the mutagenic effect of Aa at the hypoxanthine‐guanine phosphoribosyl transferase ( hprt ) locus in human lymphocytes in vitro by using the T‐cell cloning technique and selection of mutant cell clones in medium containing thioguanine. Cells treated with 1.2 — 2.4 mM Aa for 24 hr or 0.2 — 0.6 mM Aa for 48 hr showed a dose‐dependent decrease of cell survival and a 3‐ to 16‐fold increase of the mutant frequency. The inverse relationship between cell survival and mutant frequency was linear down to a relative survival of 15%, and showed a similar slope in the 24‐hr and 48‐hr treatment experiments. Forty‐one mutant T‐cell clones derived from cultures treated with 1.2 or 2.4 mM Aa and 15 from untreated controls were expanded for DNA extraction and Southern blot analysis to study deletion mutation using a full length hprt cDNA probe, and clonal identity on the basis of T‐cell receptor rearrangements. In the culture with a 16‐fold increase of mutant frequency, 4 out of 10 independent mutants (40%) showed partial deletions extending beyond the 3′ coding sequences of the hprt gene. Two of 22 independent mutants derived from the other treated cultures with at most a 6‐fold increase of mutant frequency, and 1 of 11 independent control clones showed rearrangement of the hprt gene, none of which affected the 3′‐end of the hprt gene. These results show that Aa is capable of inducing gene mutation at the hprt locus in human cells, and suggest that deletion mutation affecting the 3′‐end of the gene may be a major type of Aa‐induced mutation of this locus.