N6-Methyladenosine RNA Modification Landscape in the Occurrence and Recurrence of Nasopharyngeal Carcinoma.

Background: Nasopharyngeal carcinoma (NPC) is a type of squamous head and neck cancer with variable geographic distributions, with the highest incidence in Southeast Asia. Its primary treatment is radiotherapy due to its high radio sensitivity. However, the N6-methyladenosine (m6A) landscape in NPC, including recurrent NPC, has not been reported. Methods: In this study, m6A RNA immunoprecipitation (RIP) sequencing and microarray sequencing were performed on 12 tissue samples tissues of patients with primary and recurrent NPC. The expression profiles of m6A-related and non-coding RNAs were constructed and explored. Then, function experiments were performed to evaluate the effects of methyltransferase (METTL)3, METTL14 and WT1 associated protein (WTAP) on progressions of NPC. Finally, immunohistochemistry (IHC) and survival analysis were performed to confirm the correlation between METTL3, METTL14 and WTAP and NPC patients' clinical outcomes. Results: This study mapped m6A RNA modification and RNA expression profiles in normal nasopharynx, primary NPC, and recurrent NPC tissues. This study also explored the role of m6A modificators in NPC development and recurrence. METTL3, METTL14, and WTAP could promote invasion and metastasis of NPC, and that these three proteins could induce radiotherapy resistance in NPC cells through DNA repair. Moreover, we found that METTL3, METTL14, and WTAP promoted an increase in exosomes within NPC microenvironment. Conclusions: This study suggests that the alteration of m6A modification in primary and recurrent NPCs may play an important role in the development and progression of NPC.