Human herpes simplex-1 and papillomavirus type 16 homologous DNA sequences in normal, potentially malignant and malignant oral mucosa.

We have tested a range of normal, potentially malignant and malignant oral mucosal biopsies tissues by Southern blot hybridisation analysis for the simultaneous presence of HSV-1 and HPV type 16 DNA sequences, both of which have been implicated as risk factors in oral carcinogenesis. The results show that: (1) 2/4 patients with lichen planus, 2/4 patients with non-specific keratosis, 1/8 patients with oral carcinoma and 3/5 biopsy specimens of normal oral mucosa contained DNA sequences homologous to the HSV-1, Bam HI-G fragment. (2) HPV-16 homologous DNA sequences were detected in 3/4 patients with lichen planus, 4/4 non-specific keratosis, 4/8 oral carcinomas and in 3/5 biopsy specimens of normal oral mucosa. (3) Overall, only 5 patient biopsy specimens were positive for both HSV-1 and HPV-16 homologous DNA sequences; 2 lichen planus, 2 non-specific keratosis and 1 normal. The data cannot exclude a "hit and run" oncogenic mechanism for HSV but suggest that if HSV-1 and HPV-16 play a synergistic role in the development of oral cancer this may be an early event. Indeed, the data suggest HSV might be more frequently found in potentially malignant lesions than in carcinoma.