Physical state and expression of human papillomavirus in laryngeal carcinoma and surrounding normal mucosa

Epidemiologic and biomolecular evidence suggests that human papillomavirus (HPV) infection may be associated with the development of head and neck can cers. To clarify the role of HPV in larynx carcinoma, 25 patients were stud ied for the presence of viral DNA, possible virus integration into the cell ular genome, and vital expression both in neoplastic tissues and in neighbo uring normal mucosa. Twelve of 25 patients with neoplasia (48%) showed nega tive results for HPV sequences, and 13 (52%) showed positive results. Among the latter group of patients, seven were HPV-16 positive, five were HPV-6, and one was HPV-45. No multiple infections were detected. The physical sta tus of the HPV genome was analysed by three methods: polymerase chain react ion (PCR), bidimensional agarose gel electrophoresis, and in situ hybridisa tion. Viral integration into the host genome occurred in 43% of cases of HP V-16 and in 20% of cases of HPV-6. Viral RNA expression was detected by rev erse transcription-PCR only in HPV-16-positive tumours. The pattern of expr ession was consistent with an active role of HPV in cellular transformation . In conclusion, the present work suggests that HPV infection may be involv ed in some cases of laryngeal carcinoma. However, the transformation mechan isms might be different from those currently accepted for anogenital cancer s. J. Med. Virol. 60:396-402, 2000. (C) 2000 Wiley-Liss, Inc.