Quantitative detection of spliced E6-E7 transcripts of human papillomavirus type 16 in cervical premalignant lesions.

The splicing patterns of E6-E7 transcripts of human papillomavirus type 16 (HPV16) in cervical premalignant lesions were quantitatively analyzed by S1 nuclease protection assay. The major E6-E7 transcripts in HPV16-containing cervical lesions (four cervical intraepithelial neoplasias and one invasive carcinoma) were from spliced E6*I/E7 mRNA. The unspliced E6/E7 mRNA, which can encode the full-length zinc finger protein E6, is expressed as 8 to 15% of E6-E7 transcripts. The spliced E6*II/E7 mRNAs were expressed as 14 to 24% of E6-E7 transcripts in most tissues. However, in HPV 16-containing cell lines, the expression levels of spliced and unspliced E6-E7 transcripts were variable.