Gene-gene and gene-environmental interactions of p53, p21, and IRF-1 polymorphisms in Korean women with cervix cancer

Background: The aim of this study was to identify gene-gene and gene-environmental factors affecting cervix carcinogenesis in Korean women. Methods: We evaluated 530 subjects composed of 185 female cervix cancer patients and 345 normal healthy women. The single nucleotide polymorphisms (SNPs) of p53 codon 72, p21 codon 31, and interferon regulatory factor-1 (IRF-1) intron 6 were evaluated from extracted DNA of peripheral blood with an automatic DNA sequencer. The differences of each SNP, gene-gene and gene-environmental interactions between normal controls and patients were evaluated in the adjusted environmental background. Results: In the environmental aspect, the rate of cervix cancer increased in the women with a lower level of education, a younger age at first sexual intercourse and more childbearing. The women who had p53 (Arg/Arg), IRF-1 (T/T), and <6 years of education showed a 14.7-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), IRF-1 (∼C), and >15 years of education. The women who had p53 (Arg/Arg), p21 (Ser/Ser), and >3 children showed a 6.4-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), p21 (∼Arg), and no children. The women who had p53 (Arg/ Arg), IRF-1 (T/T), and first sexual intercourse before 22 years old showed a 5.5-fold increased risk of cervix cancer compared to the women who had p53 (∼Pro), IRF-1 (∼C), and first sexual intercourse after 26 years old. Conclusions: We found that the level of education, the age at first intercourse, and the number of children were independent risk factors in cervix carcinogenesis. The specific combinations of p53, p21, and IRF-1 gene-gene and gene-environmental interactions were significantly noted in the cervix carcinogenesis of Korean women.