The N6-methyladenosine pattern of MAP3K7 mediates the effects of sevoflurane on macrophage M2 polarization and cervical cancer migration and invasion

Introduction:
The study was designed to determine whether and how sevoflurane (Sev) regulates tumor associated macrophage (TAM) polarization and cervical cancer (CC) cell progression.

Material and methods:
The M2 polarized THP-1 was treated with 3%Sev. The culture supernatant of M2 polarized THP-1 was co-cultured with the CC cell line Hela. The NF-κB activity was determined by luciferase reporter assay. The key genes dis-regulated by 3%Sev were determined by RNA sequencing (RNA-seq) followed by real-time reverse transcription PCR (qRT-PCR) assay. Luciferase reporter assay was used to analyze the function of 3%Sev based on N6-methyladenosine (m6A) site activity on MAP3K7 3' untranslated regions (3' UTRs). RNA immunoprecipitation (IP) using an anti-m6A antibody (anti-m6A RNA-IP) was performed to determine the m6A levels at MAP3K7 3' UTR.

Results:
3%Sev treatment significantly up-regulated the M2 polarization markers and down-regulated the NF-κB activity of THP-1. Meanwhile, 3%Sev treated macrophages could enhance the migratory and invasive potential of CC cells. Further, 3%Sev significantly regulated the NF-κB pathway, including MAP3K7 inhibition. MAP3K7 overexpression reversed the 3%Sev-regulated NF-κB activity and M2 polarization. 3%Sev treatment increased m6A levels in the 3' UTR of MAP3K7. Mutational analysis of potential m6A sites within MAP3K7 3' UTR revealed that these sites were required for 3%Sev regulation. In conclusion, the m6A pattern of MAP3K7 mediates the effects of 3%Sev on macrophage M2 polarization and cervical cancer progression.

Conclusions:
3%Sev enhanced TAMs M2 polarization through regulating the m6A pattern of MAP3K7, and therefore enhanced the stimulatory effect of M2 TAMs on the migration and invasion of CC cells.