Table 1. CircRNA expression profiles in cancer tissues and cell lines.

Cancers	CircRNAs	Expression level	Samples	Mechanisms	Refs
Oral carcinoma	circRNA_100290	Up	Tissues	MiR-29 sponge	[11]
Osteosarcoma	circUBAP2	Up	Tissues	MiR-143 sponge	[13]
Thyroid carcinoma	hsa_circRNA_100395	Down	Tissues	Interaction with miR-141-3p/200a-3p	[17]
Renal carcinoma	circHIAT1	Down	Tissues	MiR-195-5p/29a-3p/29c-3p sponge	[27]
Glioma	cZNF292	Up	Cells	Promoting Wnt/β-catenin signaling	[47]
	ciRS-7	Down	Tissues/Cells	MiR-671-5p targets	[49]
Lung cancer	circRNA_100876	Up	Tissues	–	[50]
	hsa_circ_0013958	Up	tissues/Cells/Plasma	MiR-134 sponge	[51]
	cir-ITCH	Down	Tissues	Inhibiting Wnt/β-catenin signaling	[52]
Hepatic carcinoma	circZKSCAN1	Down	Tissues	Regulating cancer-related pathways	[53]
	hsa_circ_0005075	Up	Tissues	MiR-23b-5p sponge	[56]
	hsa_circ_0001649	Down	Tissues	–	[57]
	circRNA_100338	Up	Tissues/Cells	MiR-141-3p sponge	[58]
	hsa_circ_0004018	Down	Tissues	Interaction with miR-30e-5p/626	[59]
	ciRS-7	Up		Targeting miR-7	[60]
	ciRS-7	No significance	Tissues	–	[61]
Colorectal cancer	circ-BANP	Up	Tissues	Promoting Akt phosphorylation	[65]
	hsa_circ_0000069	Up	Tissues	–	[66]
	circCCDC66	Up	Tissues	Regulating a subset of oncogenes	[67]
	circRNA_001569	Up	Tissues	MiR-145 sponge	[68]
	has_circ_0020397	Up	Cells	Promoting the miR-138 target genes	[69]
	hsa_circ_001988	Down	Tissues	–	[70]
Gastric cancer	hsa_circ_0000190	Down	Tissues	–	[30]
	circRNA-0026	Down	Tissues	Regulating cancer-associated miRNAs	[76]
	circPVT1	Up	Tissues	MiR-125 family sponge	[77]
	hsa_circ_0000096	Down	Tissues	Inhibiting cyclin D1, CDK6 and MMP2/9	[78]
	circRNA_100269	Down	Tissues/Cells	Targeting miR-630	[79]
	hsa_circ_0001895	Down	Tissues/Cells	–	[80]
	has_circ_0003159	Down	Tissues	–	[81]
Leukemia	f-circRNAs	Up	Cells	–	[86]
	hsa_circ_0004277	Down	Tissues	–	[88]
Bladder carcinoma	circRNA MYLK	Up	Tissues	Binding competitively miRNA-29a family	[90]
	circTCF25	Up	Tissues	miR-103a-3p/107 sponge	[91]
Esophageal carcinoma	has_circ_0067934	Up	Tissues/Cells	–	[93]
Breast cancer	has_circ_100219	Down	Tissues	Sequestering miRNAs	[96]
	circDENND4C	Up	Cells	HIF1α dependent	[97]
	circ-ABCB10	Up	Tissues	MiR-1271 sponge	[98]
	circ-Amotl1	Up	Tissues/Cells	inducing c-Myc nuclear translocation	[99]