RESUMEN
BACKGROUND: Uterine leiomyomas could be considered as benign tumor of human uterus smooth muscle with unknown etiology and pathophysiology.Furthermore, they are the most common indication of hysterectomy. The tumor suppressor gene p53 has been involved in various malignancies. Mutation in its promoter site may play a role in tumorigenesis of many malignancies including leiomyompa. MATERIALS AND METHODS: For study of polymorphisms and allele frequency, 234 female patients with pathologically diagnosed uterine leiomyoma and 100 healthy blood donors as control group were assessed. DNAs were extracted from peripheral blood cells, amplified using polymerase chain reaction and restriction fragment length polymorphism (RFLP) technique was utilized for their analysis. RESULT: Proportions of A homozygote/heterozygote/G homozygote for SNP -250 A/G in leiomyoma group were 97.8%, 1.7%, and 0.4%, and in control group 97%, 3%, and 0%, respectively. In case of -216 T/C polymorphism, proportions of T homozygote/heterozygote/C homozygote in leiomyoma were 98%, 1.7%, and 0%, and in control samples 98%, 2%, and 0%, respectively. Genotype frequency of A homozygote/heterozygote/G homozygote for SNP-103 A/G was 97.9%, 1.7%, and 0.4% in leiomyoma group, and 98%, 2%, and 0% in control group, respectively. Proportions of A homozygote/heterozygote/G homozygote for SNP-33 A/G in leiomyoma group were 97.8%, 2.2%, and 0%, and 97%, 3%, and 0% in case samples, respectively. DISCUSSION: Based on the present results in an Iranian female population, surprisingly there was no significant differences between leiomyoma cases and control samples regarding allele frequencies of p53 promoter polymorphism.Therefore, The p53 promoter polymorphism is not associated with the susceptibility of uterine leiomyomas in Iranian women.
Asunto(s)
Predisposición Genética a la Enfermedad , Leiomioma/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Proteína p53 Supresora de Tumor/genética , Neoplasias Uterinas/genética , Adulto , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Persona de Mediana Edad , Neoplasias Uterinas/etiologíaRESUMEN
The restriction site mutation (RSM) assay (see Steingrimsdottir et al. [H. Steingrimsdottir, D. Beare, J. Cole, J.F.M. Leal, T. Kostic, J. Lopez-Barea, G. Dorado, A.R. Lehmann, Development of new molecular procedures for the detection of genetic alteration in man, Mutat. Res. 353 (1996) pp. 109-121] for a review) has been developed as a genotypic mutation detection system capable of identifying mutations occurring in restriction enzyme sites of genomic DNA. Here we will report the steps taken to overcome some of the initial problems of the assay, namely the lack of quantitative data and limited sensitivity, the aim being to achieve a methodology suitable for the study of low dose chemical exposures. Quantitative data was achieved in the RSM assay by the inclusion of an internal standard molecule in the PCR amplification stage, thus allowing the calculation of both spontaneous and induced mutation frequencies. The sensitivity of the assay was increased through the discovery that intron sequences of genomic DNA accumulated more mutations in vivo compared to the exons, presumably due to differential selective pressure within genes [G.J.S. Jenkins, I.deG. Mitchell, J.M. Parry, Enhanced restriction site mutation (RSM) analysis of 1, 2-dimethylhydrazine-induced mutations, using endogenous p53 intron sequences, Mutagenesis 12 (1997) pp. 117-123]. This increased sensitivity was examined by applying the RSM assay to analyse the persistence of N-ethyl-N-nitrosourea (ENU)-induced mutations in mice testes. Germ line mutations were sought in testes DNA 3, 10 and 100 days after ENU treatment. Mutations were detected in exons and especially intron regions, the intron mutations were more persistent, still being detected 100 days post-chemical treatment. Assignment of these mutations as ENU induced was complicated in some cases where the spontaneous mutation level was high. This theme of mutation persistence was further investigated by studying the presence of 4-nitroquinoline-1-oxide (4-NQO)-induced DNA mutations in vitro. This study also analysed the relationship between DNA adduct formation and DNA mutation induction by the concurrent RSM analysis and 32P post-labelling analysis of 4-NQO treated human fibroblasts. The results demonstrated that early DNA mutations detected 4 days post-treatment by the RSM assay were probably ex vivo mutations induced by Taq polymerase misincorporation of 4-NQO adducted DNA, due to the maximum levels of 4-NQO adducts being present at this time point. A later mutational peak, after the adduct level had declined, was assumed to be due to DNA sequence changes produced in the fibroblasts by the in vivo processing of DNA adducts.