HPV 16 mutations associated to oral cancer

Abstract

Human Papillomavirus (HPV) is the most frequent sexually transmitted infection (STI) worldwide and despite the well-established role of HPV in cervical cancer, new lines of studies evidence that HPV may also be an independent risk factor for head and neck cancers. HPV16 variants and point mutations differ in their ability to establish persistent infections and development of malignancy. HPV16 variants are divided into six lineages: European (EUR), African (AFR 1 and 2), Asian (As), Asian American (AA) and North American (NA).

The aim of this study was to describe the lineages and genetic variability of the E6 and LCR region in the HPV16 sequences obtained from oral cavity lesions samples of patients from Córdoba city. 

Oral swabs were taken from different type of oral lesions, identify by specialized stomatology dentist from Faculty of Dentistry, previously. Samples were analysed using PCR method to E6 and LCR HPV16 genes and Sanger sequencing. Genetic sequences and phylogenetic trees were analysed using MEGA6 software. 

A total of 23 oral sequences to E6 gene and 8 to LCR gene, were studied. The more frequent point mutations were T350G in 18 sequences and G7521A in 7 sequences, to E6 and LCR genes, respectively. In this study, other point mutations were described too. Concern to HPV16 lineages, all E6 sequences belonged to EUR variant, 7 sequences of LCR were EUR too and 1 of them was AFR2 variant. 

This is the first study of lineages and point mutations obtained from oral lesions samples in Argentina. Point mutations associated to malignancies were identify in benign lesions, potentially malignant oral disorders and oral squamous cell carcinomas, highlighted the importance of studying and being able to follow the evolution of the lesion over time, to could offer a correct treatment to the patient. HPV16 infection is a potential risk factor to oral lesions and the knowledge of genetic variations could be an important point to oral cancer prevention.