Impact of HPV infection on gene expression and methylation in oral cancer patients.

Purpose: The current study aimed to examine the association between head and neck squamous cell carcinoma (HNSCC) and infection with different human papillomavirus virus (HPV) subtypes, including analysis of promoter methylation of several genes (APC, CDKN2A, MGMT, CDH1 and TIMP3) and the correlation with their mRNA expression in tumours and surgical margins.

Methodology: In 47 patients with a primary tumour of the oral cavity, HPV detection and identification of 33 subtypes was performed after previous DNA isolation using a GenoFlow HPV Array Test Kit.

Results: Fifteen patients (31.92 %) were HPV [+] and the following HPV types were detected: 16 (46.67 %), 18 (6.67 %) and 43/44 (40 %). This study is the first to describe HPV 43/44 subtypes in HNSCC in a Polish population. We noted no clinical significance of HPV [+] HNSCC compared to HPV [-], however, this differed among HPV subtypes. CDKN2A promoter methylation was more frequent in HPV-16/18 patients compared to HPV43/44 patients, but there was no difference in gene expression level between HPV [+] and [-] patients.

Conclusion: We detected HPV infection in 31.92 % of oral cancer cases. HPV 16, along with HPV 43/44, were the most frequent subtypes. Knowledge of HPV [+] HNSCC biology may be useful in establishing the prognosis and developing novel therapies in future.