Detection of human papillomavirus type 16 E6/E7 oncogene transcripts in dysplastic and nondysplastic cervical scrapes by nested RT-PCR.

Infections with high-risk human papillomaviruses (e.g., HPV-16) play an important role in the development of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (IC). Continued expression of the viral E6 and E7 genes is believed to be a key factor for oncogenic transformation of infected cells. Two spliced transcripts of the E6/E7 oncogenes, termed E6I and E6II, can be detected by reverse transcriptase polymerase chain reaction (RT-PCR). To increase the sensitivity of detecting E6/E7 transcripts in cervical scrapes we took advantage of a nested RT-PCR (nRT-PCR) protocol. In a series of 30 HPV-16-positive patients with histologic diagnoses ranging from nondysplastic epithelium to IC, the application of nRT-PCR significantly improved the detection of E6/E7 transcripts compared to conventional RT-PCR. The prevalence of E6/E7 spliced transcripts correlated with lesion severity and the nRT-PCR protocol allowed detection of these transcripts even in nondysplastic epithelium and CIN I lesions. Therefore, in epidemiologic follow-up studies, detection of E6/E7 transcripts by nRT-PCR should prove to be a useful diagnostic tool for risk evaluations regarding the development of CIN and its progression to cervical cancer, especially in high-risk HPV-type-infected patients with CIN 0 and CIN I.