Table 2.

Roles of m⁶A methylation on circRNAs

m6A regulators	circRNA	m6A levels	Effects on circRNAs	Diseases	References
ALKBH5/METTL3	a subset of circRNAs	decrease/increase	modulate the biogenesis	spermatogenesis	Tang et al.88
METTL3/YTHDC1	circ-ZNF609	increase	modulate the biogenesis	rhabdomyosarcoma tumors	Di Timoteo et al.107
METTL3	hsa_circ_0029589	increase	decrease its expression	ACS, AS	Guo et al.108
METTL3/YTHDC1	circ-ARL3	increase	promote splicing and biogenesis	HCC	Rao et al.109
METTL3	circ1662	increase	induce its expression	CRC	Chen et al.110
METTL3	circMETTL3	increase	regulate its expression	breast cancer	Li et al.111
METTL3/YTHDC1	circHPS5	increase	promote biogenesis and nucleus-cytoplasm output	HCC	Rong et al.112
KIAA1429	circDLC1	increase	regulate its expression	HCC	Liu et al.113
METTL3/FTO/YTHDF1/2	circRNA-SORE	increase	enhance its stability	HCC	Xu et al.114
METTL3	circCUX1	increase	stabilize its expression	hypopharyngeal squamous cell carcinoma	Wu et al.115
METTL3	circ0000069	increase	improve its stability	cervical cancer	Chen et al.116
YTHDF3/eIF4G2	circ-ZNF609	recognition	increase translation	HeLa cells	Di Timoteo et al.107
METTL3/METTL14	circE7	increase	facilitate translation	human papillomavirus	Zhao et al.117
FTO	circRNA ARHGAP35	decrease	promote translation	HCC	Li et al.118
YTHDF2	circRNA	recognition	suppress immunity	mammalian cells	Chen et al.119
YTHDC1	circNSUN2	recognition	export to cytoplasm from nucleus	CRC	Chen et al.120
METTL14	circGFRα1	increase	export to cytoplasm from nucleus	FGSCs	Li et al.121
METTL3/METTL14	circNDUFB2	increase	impair interaction with proteins	NSCLC	Li et al.122