104P - Hypomethylated immune gene promoters as potential biomarkers in oral and oropharyngeal cancer

Background

The proportion of oral and oropharyngeal squamous cell carcinoma (OOSCC) that can be attributed to human papillomavirus (HPV) infection is growing nowadays. A potential factor indicating the occurrence of HPV-positive OSCC is a change in the degree of methylation of gene promoters that play a key role in the immune response. In this study, we investigated the difference in methylation of bunch of gene promoters expected to be differently methylated in head and neck cancer versus healthy oral mucosa.

Methods

The presence of HPV infection in samples was examined earlier. To determine the difference in methylation of those gene promotors, isolated and bisulfite-modified DNA was analysed by Methylation Specific PCR method (MSP). The standard Chi-square test was used for the comparison of two groups of samples. Spearman’s correlation was used, and the Spearman’s rank correlation coefficient between groups’ data is calculated.

Results

The best potential biomarkers were EDARADD, GBP4, HAVCR2, HLA DPB1, IL12RB1, MARCO, and SIGLEC12 gene promoters. They found to be more hypomethylated in the oral and oropharyngeal cancer samples in comparison to normal tissue. In samples of healthy oral mucosa, the investigated gene promoters were found to be methylated in a very high percentage, up to 100%, while in oral and oropharyngeal cancer samples, they were methylated in a very low percentage, about 20 %, regardless of HPV infection.

Conclusions

In conclusion, methylation of immune gene promoters may be good potential biomarker of head and neck cancer, primarily OOSCC, and possibly, indicator of prognosis and progression of individual OOSCC.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

The Ruđer Bošković Institute.

Funding

European Social Fund.

Disclosure

All authors have declared no conflicts of interest.