RESUMEN
We performed a case-control association study to evaluate the association between common polymorphisms in MTHFR (C677T and A1298C) and the Arg72Pro polymorphism in the p53 gene and the risk for cervical intraepithelial neoplasia (CIN) or invasive cervical cancer (ICC) in Mexican HPV-infected women. We included 131 women with diagnosis of CIN grade I-II and 78 with CIN III or ICC; as controls we also included 274 women with normal Pap smear and negative HPV test. Genotyping for MTHFR and p53 polymorphisms was performed by PCR-RFPLs. HPV was tested by Hybrid Capture II. Odds ratios and 95% confidence intervals were estimated. Genotype frequencies for the 3 studied polymorphisms were distributed according to the Hardy-Weinberg equilibrium. The A1298C-MTHFR polymorphism showed significant differences for the heterozygous AC genotype and the C allele, whereas the AA genotype and A allele resulted to be genetic risk factors for CIN or ICC (p<0.03). The Arg72Pro-p53 polymorphism showed for the genotypes Arg/Pro and Pro/Pro, and for the Pro allele, a significant association only to the risk for CIN (p<0.03). The MTHFR/p53 interaction showed that the genotype combinations AA/ArgArg and AA/ArgPro were associated, respectively, to the risk of ICC and CIN (p<0.05). This study suggests that the A1298C-MTHFR polymorphism contributes to the genetic risk for both CIN and ICC, whereas the Arg72Pro-p53 polymorphism only contributes to the risk for CIN. The MTHFR/p53 genetic combinations AA/ArgArg and AA/ArgPro are associated genetic risk factors for ICC and CIN in Mexican HPV-infected women.
Asunto(s)
Genes p53 , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Infecciones por Papillomavirus/genética , Displasia del Cuello del Útero/genética , Neoplasias del Cuello Uterino/genética , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , México , Persona de Mediana Edad , Infecciones por Papillomavirus/enzimología , Polimorfismo Genético , Factores de Riesgo , Neoplasias del Cuello Uterino/enzimología , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/enzimología , Displasia del Cuello del Útero/virologíaRESUMEN
Infection with some genotypes of human papillomavirus (HPV) is the most important risk factor associated with cervical cancer (CC). Throughout the world, HPV type 58 prevalence varies from one region to another; it is higher in women from certain countries in Asia and Latin America, such as China and Mexico. Although intratypic variants have been reported on a few occasions, our knowledge about HPV 58 genetic variation remains limited. Therefore, this work aims to (i) determine the prevalence of HPV type 58 amongst Mexican women with invasive CC or precursor lesions and (ii) identify HPV 58 sequence variants. One hundred and forty five colposcopy clinic patients were studied. Genotyping of HPV 16, 18 and 58 was determined by specific nested PCR and HPV 58 variants were detected by direct sequencing. The general prevalence of HPV was 51.7% (75/145). HPV 16 was found in 30.6% (23/75) and HPV 58 in 24% (18/75) of the patients. HPV 18 was not identified in patients with cervical intraepithelial neoplasia (CIN) grade I; it was only found in those with CIN II, with a prevalence of 6.8% (3/44). In patients with CC, the prevalence of HPV 16 and 58 was 78.9%. Regarding HPV 58 variants, 94.4% of the HPV 58 sequences were identical to the prototype strain, whereas one sample showed changes at a single nucleotide. This study demonstrates a high prevalence of HPV 58 and a low genetic variability of E6 sequences amongst Mexican colposcopy patients.
Asunto(s)
Alphapapillomavirus/genética , Proteínas de la Cápside/genética , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/virología , Lesiones Precancerosas/virología , Displasia del Cuello del Útero/virología , Neoplasias del Cuello Uterino/virología , Alphapapillomavirus/clasificación , Alphapapillomavirus/aislamiento & purificación , ADN Viral/genética , Femenino , Variación Genética , Genotipo , Humanos , México/epidemiología , Estadificación de Neoplasias , Infecciones por Papillomavirus/epidemiología , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo , Neoplasias del Cuello Uterino/epidemiología , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/epidemiologíaRESUMEN
Infection with some genotypes of human papillomavirus (HPV) is the most important risk factor associated with cervical cancer (CC). Throughout the world, HPV type 58 prevalence varies from one region to another; it is higher in women from certain countries in Asia and Latin America, such as China and Mexico. Although intratypic variants have been reported on a few occasions, our knowledge about HPV 58 genetic variation remains limited. Therefore, this work aims to (i) determine the prevalence of HPV type 58 amongst Mexican women with invasive CC or precursor lesions and (ii) identify HPV 58 sequence variants. One hundred and forty five colposcopy clinic patients were studied. Genotyping of HPV 16, 18 and 58 was determined by specific nested PCR and HPV 58 variants were detected by direct sequencing. The general prevalence of HPV was 51.7 percent (75/145). HPV 16 was found in 30.6 percent (23/75) and HPV 58 in 24 percent (18/75) of the patients. HPV 18 was not identified in patients with cervical intraepithelial neoplasia (CIN) grade I; it was only found in those with CIN II, with a prevalence of 6.8 percent (3/44). In patients with CC, the prevalence of HPV 16 and 58 was 78.9 percent. Regarding HPV 58 variants, 94.4 percent of the HPV 58 sequences were identical to the prototype strain, whereas one sample showed changes at a single nucleotide. This study demonstrates a high prevalence of HPV 58 and a low genetic variability of E6 sequences amongst Mexican colposcopy patients.
