Correlation between human herpesvirus-6 and oral squamous cell carcinoma pathogenesis

Objectives:To investigate the correlation between human herpesvirus-6's infection and pathogenesis of oral squamous cell carcinoma,as well as its clinical significance. Methods: Samples of saliva, peripheral blood mononuclear cells (PBMCs) and tissue were collected from 82 patients with oral squamous cell carcinoma, 25 patients with oral precancerous lesions and 40 healthy young adults. Nested PCR assay was used for diagnosis of HHV-6 infections. Results: (1)For control group, precancerous lesions group and carcinoma group, HHV-6's positive rates were 45.0%,56.0%,72.0% in saliva , 22.5%,48.0%,57.3% in PBMCs and general rate were 47.5%,56.0%,80.5%, which all had statistical differences(P<0.01); (2) HHV-6 DNA positive rates in saliva were higher than those in PBMCs, among which control group and carcinoma group had statistical differences(P<0.05) while precancerous lesions group had not; In carcinoma group, the positive rate in cancer tissues (78.95%) was significantly higher than that in normal tissues(10.53%)(P<0.01); (3) With carcinoma differentiation level's decrease, HHV-6's positive rates showed a descending tendency while existed no statistical difference (P>0.05) Conclusions: The results indicate that: (1) saliva gland is the position of HHV-6's latency/proliferation and saliva is the predominant route of transmission. Drawing materials from saliva can make clinical and laboratory work efficient and painless; (2) HHV-6's infection correlates to pathogenesis of oral squamous cell carcinoma and may play a role as an initiation factor; (3) HHV-6'activation occurs in the pathological change's forepart and may take part in cell transformation, so the auxiliary anti-virus therapy can be considered in the early stage; (4) Nested-PCR assay is responsive and convenient in detecting virus, which is of good prospect in clinical application. Supported by the National Natural Science Foundation of China (Grant No. 39270034)