Simultaneous in situ hybridization for DNA and RNA reveals the presence of HPV in the majority of cervical cancer cells

Summary Thirteen cases of invasive squamous cell carcinoma of the uterine cervix containing HPV types 16 or 18 DNA sequences, as detected by Southern blot analysis, were investigated by in situ hybridization on routine paraffin sections, using 3SS nick-translated DNA probes. Simultaneous in situ hybridization for DNA and RNA showed that in ten out of 13 cases (77%) the percentage of tumor cells containing HPV 16 or 18 varied from 75 to 100%. In onecase, harboring both in situ and invasive carcinoma, the same type of HPV DNA was detected in both components. This finding suggests that neoplastic cells retained the viral genome during progression to invasiveness.