Table 2.

The role of m6a modification in non-coding RNA processing

RNA processing	m6A regulator	Mechanism	Function	References
miRNA processing	METTL3	promotes binding to HNRNPA2B1, DGCR8 and Dicer by methylating pri-miRNAs	promotes pri-miRNA processing	[117, 118]
	METTL3	promotes miR-221/miR-222 processing, leading to reduced PTEN expression	promotes Bca progression	[119]
	METTL3	enhances processing maturation of miR-1246 via m6a methylation	promotes CRC progression	[120]
	METTL14	METTL14-mediated methylation modification of m6a affects binding of pri-miR-126 to DGCR8	Inhibition of HCC growth	[121]
	ALKBH5	mediates miRNA demethylation by interacting with DDX3	Regulates cell growth and proliferation	[122]
	HNRNPC	Silencing of HNRNPC reduces miR-21 expression, thereby inhibiting the AKT-p70S6K pathway	Promote GBM cell migration and invasion	[123]
	NKAP	mediates the maturation of m6A-modified pri-miR-25, leading to a decrease in PHLPP2 expression, which promotes the activation of AKT signalling	promotes Pancreatic cancer progression	[124]
	TARBP2	Modifying dependencies via m6a	Regulation-miRNA processing maturation	[125–128]
	HNRNPA2B1	inhibits miR-29a-3p, miR-29b-3p and miR-222 expression	endocrine resistance in breast cancer cells	[129]
lncRNA structure	HNRNPC	"m6a switch" mechanism	Structural changes	[136]
lncRNA stability	METTL3	enhances MALAT1 stability	promotes IDH-wildtye glioma progression	[134]
	VIRMA	Enhances CCAT1, CCAT2 stability	ncreases Pca invasiveness	[135]
	METTL3	increases ABHD11-AS1 stability	promotes NSCLC progression	[136]
	METTL3	stabilizes FAM225 and initiates ceRNA model	promotes NPC progression	[138]
	METTL3	stabilizes RHPN1-AS1 and initiates ceRNA model	promotes ovarian cancer	[139]
	METTL3	stabilizes LINC00958 and initiates ceRNA model	promotes adipogenesis and progression of HCC	[140]
circRNA biosynthesis	METTL3	YTHDC1 direct the back-splicing reaction CircZNF609	Regulation of circRNA synthesis	[147]
	METTL3	installs m6a in the reverse complementary sequence of the circ1662 flanking intron to promote circRNA production	promotes CRC invasive metastasis	[148]
circRNA nuclear export	YTHDC1	enhances the stability of HMGA2 mRNA by generating the RNA–protein ternary complex circNSUN2/IGF2BP2/HMGA2	promotes colorectal cancer metastasis	[149]
	METTL14	Recognition of the GGACU structure promotes the export of m6A-modified circGFRα1	Promotes nuclear export	[150]
circRNA translation	METTL3	YTHDF3 cap-independent start translation	Driving translation	[147, 158]
	METTL3	Promotes circE7 translation	Promotes cervical cancer progression	[163]
circRNA stabilization	YTHDF2	formation of the YTHDF2-HRSP12-RNase/MRP complex	circRNA degradation	[152]
	METTL3	stabilizes circ0000069 and initiates ceRNA model	promotes cervical cancer progression	[155]

BCa bladder cancer, CRC colorectal carcinoma, NSCLC non-small-cell lung cancer, HCC Hepatocellular carcinoma, NPC nasopharyngeal carcinoma