The mutational spectrum of the HPRT gene from human T cells in vivo shares a significant concordant set of hot spots with MNNG-treated human cells.
Cancer Res
; 63(18): 5793-8, 2003 Sep 15.
Article
en En
| MEDLINE
| ID: mdl-14522901
The preponderance of G:C to A:T transitions in inherited and somatic human mutations has led to the hypothesis that some of these mutations arise as a result of formation of O(6)-methylguanine in DNA. To test this hypothesis, the fine structure map of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutations was determined in human lymphoblastoid cells in the human hypoxanthine-guanine-phosphoribosyltransferase (HPRT) gene and compared with HPRT mutations observed in somatic T lymphocytes from normal individuals. Human TK6 cells, which are methylguanine methyltransferase deficient (MGMT(-)), were treated with the methylating agent MNNG to create a level of O(6)-methylguanine in cellular DNA equal to that found in normal human tissues. A total of 676 bp of the HPRT gene was scanned using constant denaturing capillary electrophoresis and high-fidelity PCR. MNNG induced 14 predominant hot spots, all which were G:C to A:T transitions. Thirteen of these 14 MNNG-induced hot spots were found among the in vivo set, and 10 of the MNNG-induced hot spots were among 75 putative in vivo hot spots (mutations observed two or more times in vivo). Using a hypergeometric test for concordance, the MNNG-induced hot spots were found to be a significant subset of the putative in vivo hot spots (P < 4 x 10(-7)). The set of shared hot spots comprise some 18% of the HPRT in vivo hot spot spectrum and strongly suggest that MNNG-induced hot spots in vitro share a common mutational pathway with a significant subset of somatic mutations in vivo.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Linfocitos T
/
Guanina
/
Hipoxantina Fosforribosiltransferasa
/
Metilnitronitrosoguanidina
/
Mutación
Límite:
Humans
Idioma:
En
Revista:
Cancer Res
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos