[Molecular biologic study on the carcinogenesis of HPV in uterine cervical cancer and related lesions--analysis of HPV types 16, 18 E6/E7 gene mRNA]

Abstract

Recent molecular biologic studies have shown that some type of human papillomavirus (HPV) is closely associated with uterine cervical cancer. In order to investigate the relationship between HPV DNA and cervical cancer, we studied the carcinogenesis of HPV in cervical cancer and related lesions by dot blot hybridization (D.B.H.), Southern blot hybridization (S.B.H.), in situ hybridization (I.S.H.) and polymerase chain reaction (P.C.R.). We also followed some HPV DNA, mRNA positive or negative cases of cervical dysplasia for more than 16 months prospectively. I. Analysis of HPV DNA HPV DNA were detected in cervical dysplasia and cancer and HPV positive rate increased as the grade of cervical dysplasia became higher by several molecular biologic analysis. Especially, the results of I.S.H. with biotinylated HPV DNA probes revealed that HPV DNA was located in the nuclei of koilocytosis, dysplastic cells and cancer cells. In analysis of HPV type in squamous epithelium, HPV 6/11 was the highest positive rate (21.1%) in mild dysplasia. On the other hand, HPV16 positive rate increased with the grade of dysplasia and 34.9% (15/42) of moderate dysplasia and 51.4% (18/35) of severe dysplasia were positive for HPV 16 DNA, respectively. And N/C ratio in HPV 16 positive cells significantly increased by measurement of micrometer. These findings suggest that HPV 16 is high risk HPV and associated with squamous epithelial neoplasia. About 50% of metaplasia close to cervical neoplasia with HPV DNA was positive for the same type of HPV. In columnar epithelium, several types of HPV DNA were detected in 46.7% (15/32) of cervical adenocarcinoma. Thirty one percent (10/32) of adenocarcinoma, 50% (4/8) of adenosquamous cell carcinoma were positive for HPV 18. This suggests an association between HPV 18 and adenocarcinoma and related lesions. We examined amplified DNA detection of HPV 16 and 18 E7 gene by P.C.R. method. HPV 16 and/or 18 DNA were detected in 25 of 43 cases of cervical scrapes obtained from cervical neoplasia, and we confirmed the P.C.R. is the useful method for the screening and the retrospective investigation of HPV infection. By the immunohistochemical and molecular biologic study, there was no correlation HPV DNA with c-myc product and c-myc gene amplification. II. Analysis of HPV mRNA (E6/E7, L1/L2) The early genes E6/E7 of HPV 16 and 18 were considered as one of the carcinogenic factors of uterine cervix. We investigated the localization of HPV E6/E7 and L1/L2 mRNA in cervical dysplasia and CIS with I.S.H. using antisense and sense biotinylated HPV RNA probes which were made by in vitro transcription.(ABSTRACT TRUNCATED AT 400 WORDS)