RESUMEN
By means of a consensus polymerase chain reaction (PCR) method, the prevalence of HPV types was determined in cervical biopsies from 137 women referred to the gynecological outpatient clinic for colposcopy because of an abnormal cervical smear. The prevalence of HPV was 80.3%. There was a statistically highly significant rise in the prevalence of the oncogenic HPV types (16, 18, 31, 33) with increasing severity of cervical intraepithelial neoplasia (CIN I to III), indicating a role for these HPV types in the pathogenesis of cervical cancer. The prevalence of other HPV types decreased significantly with the severity of the lesion, suggesting that these HPV types play a less significant role in this process. These data indicate that HPV typing with PCR may be a valuable tool for distinguishing between high-risk and low-risk cervical lesions. Furthermore, our results suggest that the detection of HPV types by consensus PCR in the cervix of patients with an abnormal smear but without histologically detectable CIN is a useful tool for predicting which of these patients will eventually develop CIN. Finally, a relatively low percentage (3%) of HPV double infections is reported in this study.
Asunto(s)
Cuello del Útero/patología , Infecciones Tumorales por Virus/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Biopsia , Cuello del Útero/microbiología , ADN Viral/análisis , Diagnóstico Diferencial , Femenino , Humanos , Papillomaviridae/química , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Infecciones Tumorales por Virus/patología , Neoplasias del Cuello Uterino/patologíaRESUMEN
We utilized the RNA polymerase chain reaction (PCR) to analyse the transcripts of the E6/E7 open reading frames of human papillomavirus type 16 (HPV-16). Total RNA was isolated from 14 cervical squamous carcinomas, nine cervical intraepithelial neoplasias and from human fibroblasts transformed with different HPV-16 constructs. In all specimens two spliced transcripts were detected. Sequence analysis of the cloned PCR products showed that both transcripts were generated by splicing out an intron in E6, from nucleotides (nt) 226 to 409 in one transcript and from nt 226 to 526 in the other. The major transcript present in all RNA specimens had the smallest intron in E6. The RNA PCR described here is the method of choice for analysing splice and donor sites in tissue specimens where a limited amount of RNA is available. Results obtained with transformed cells revealed no difference in splicing whether HPV-16 was controlled by its homologous promoter or by a heterologous promoter, the Rous sarcoma virus long terminal repeat.
Asunto(s)
Transformación Celular Viral , Proteínas Oncogénicas Virales/genética , Papillomaviridae/genética , Empalme del ARN , Neoplasias del Cuello Uterino/microbiología , Secuencia de Bases , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/microbiología , Células Cultivadas , Femenino , Fibroblastos , Humanos , Datos de Secuencia Molecular , Proteínas E7 de Papillomavirus , Reacción en Cadena de la Polimerasa , Lesiones Precancerosas/genética , Lesiones Precancerosas/microbiología , ARN Viral/genética , Transcripción Genética , Neoplasias del Cuello Uterino/genéticaRESUMEN
The sensitivities of dot blot hybridisation and in situ filter hybridisation for the detection of HPV DNA were compared. Dot blot hybridisation was 10-50 times more sensitive than in situ filter hybridisation in detecting HPV 16 DNA in the cervical cancer cell lines SiHa and CaSki. Cervical smears collected from 51 women with a history of one or more abnormal cervical smears were tested by both hybridisation techniques for the presence of HPV 16 DNA; 11 were positive in the in situ filter hybridisation, 35 in the dot blot hybridisation. Thirty-five cervical biopsies available from this group of 51 women were processed for dot blot hybridisation. In 30 of the 35 cases the results of this hybridisation corresponded with the results of the dot blot hybridisation on the smears.
