Detection and Phylogenetic Analysis of Torque Teno Virus in Salivary and Tumor Biopsy Samples from Head and Neck Carcinoma Patients

Abstract

Objectives: Because torque teno virus (TTV) has been implicated in tumorigenesis as a cocarcinogen, we studied TTV prevalence in saliva and biopsy samples from head and neck cancer (HNCC) patients, patients with premalignant lesions of oral cancer, and controls. We also wished to determine the TTV genotypes in HNCC patients. Methods: A seminested polymerase chain reaction (PCR) amplifying the N22 region of the TTV genome, as well as direct sequencing of PCR fragments, was used. Results: TTV prevalence was higher in HNCC patients (saliva: 27/71, 38%; tumor biopsy: 22/74, 30%) than in controls (saliva: 8/56, 14%; oral mucosa: 1/19, 5%). TTV prevalence was also high in patients with premalignant lesions of oral carcinoma (saliva: 9/18, 50%; biopsy: 5/21, 24%). By phylogenetic analysis, TTV belonging mostly to genotypes 1 and 2 was found in HNCC patients. In most of the cases, identical TTV strains were present in the biopsy and salivary sample of the same HNCC patient. In addition, the same TTV strain was detected in 2 laryngeal carcinoma biopsies obtained from 2 independent patients. Conclusions: Our data are compatible with the idea that TTV might act as a cocarcinogen in certain cases of HNCC. Alternatively, HNCC may facilitate either TTV replication or TTV entry into the saliva.