QUANTIFICATION OF HPV-16 E6-E7 TRANSCRIPTION IN CERVICAL INTRAEPITHELIAL NEOPLASIA BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION

Human papillomavirus type 16 (HPV-16) is associated with neoplastic le sions of the uterine cervix. Viral transforming functions have been lo calized to the E6-E7 open reading frame (ORF) and this ORF is conserve d consistently in cervical intraepithelial neoplasia (CIN). Two mRNAs, generated by alternative splicing, are expressed from the E6-E7 ORF. These are known as E6I and E6*II, and potentially encode the viral E7 and E6 proteins, respectively. It is believed that the HPV-16 transfo rming ability is mediated by the E6 and E7 proteins. A quantitative RT -PCR assay, developed by us to characterize the relative expression of E6-E7 spliced transcripts, was applied to exfoliated cervical cells o btained from patients in varying stages of clinically defined CIN and who were infected with HPV-16. The relationship between viral expressi on, disease stage, oral contraceptive use and age was studied. No asso ciation was observed between age or oral contraceptive use and HPV-16 E6-E7 expression. However, when both E61 and E6*II were detected, a d irect correlation was observed between relative proportions of E6I/E6 II mRNAs greater than 95%/5% and increased disease severity. This stu dy underscores the importance of the relationship between quantities o f viral transforming gene transcript and the course of cervical diseas e. It also suggests that quantification of HPV-16 E6-E7 transcription may be useful as a prognostic tool to identify women who are at increa sed risk of developing cervical cancer. (C) 1993 Wiley-Liss, Inc.