METTL14-mediated m6A modification of ETV4 inhibits tumor development in colorectal cancer.

BACKGROUND

Many m6A methyltransferases have been identified to regulate colorectal cancer (CRC) progression. METTL14 has been confirmed to play a negative role in CRC process, but the molecular mechanism of METTL14 in regulating CRC progression needs to be further elucidated.

METHODS

The levels of METTL14, YTHDF2 and ETS translocation variant 4 (ETV4) were examined by qRT-PCR and western blot. Cell proliferation and apoptosis were determined by colony formation assay and flow cytometry. Cell glycolysis was assessed by detecting corresponding indicators. Cell ferroptosis was evaluated via measuring SOD, MDA, GSH, ROS and Fe levels. The interaction between ETV4 and METTL14 or m6A readers was confirmed by RIP assay and RNA pull-down assay. Animal experiments were performed to confirm METTL14 roles in vivo.

RESULTS

METTL14 was downregulated in CRC tissues and cells, which overexpression inhibited proliferation and glycolysis, as well as promoted apoptosis and ferroptosis in CRC cells. METTL14 reduced the mRNA stability of ETV4 and inhibited ETV4 protein expression through m6A modification. m6A reader YTHDF2 could recognize m6A-methylated ETV4. The downregulation of ETV4 by METTL14 leads to increased apoptosis and ferroptosis in CRC cells, suggesting a critical role in tumor suppression. Moreover, METTL14 inhibited CRC tumorigenesis in vivo via reducing ETV4 expression.

CONCLUSION

METTL14 accelerated CRC cell apoptosis and ferroptosis via downregulating ETV4 in m6A-dependent manner, providing a molecular target for CRC treatment.