The m(6)A RNA Modification Quantity and mRNA Expression Level of RNA Methylation-Related Genes in Head and Neck Squamous Cell Carcinoma Cell Lines and Patients

RNA methylation at the nitrogen sixth of adenosine (m(6)A, N(6)-methyladenosine) is the most abundant RNA modification which plays a crucial role in all RNA metabolic aspects. Recently, m(6)A modification has been assigned to mediate the biological processes of cancer cells, but their significance in HNSCC development is still poorly described. Thus, the main aim of this study was to globally quantify m(6)A modification by the mass spectrometry approach and determine the mRNA expression level of selected m(6)A RNA methyltransferase (METTL3), demethylase (FTO), and m(6)A readers (YTHDF2, YTHDC2) in 45 HNSCC patients and 4 cell lines (FaDu, Detroit 562, A-253 and SCC-15) using qPCR. In the results, we have not observed differences in the global amount of m(6)A modification and the mRNA level of the selected genes between the cancerous and paired-matched histopathologically unchanged tissues from 45 HNSCC patients. However, we have found a positive correlation between selected RNA methylation machinery genes expression and m(6)A abundance on total RNA and characterized the transcript level of those genes in the HNSCC cell lines. Moreover, the lack of global m(6)A differences between cancerous and histopathologically unchanged tissues suggests that m(6)A alterations in specific RNA sites may specifically influence HNSCC tumorigenesis.