Table 2.
CircRNAs in digestive system cancer: signaling pathway and function
| circRNA | Cancer type | Expression in tumors | Pathway/regulatory network | Function/clinical association | Ref. |
|---|---|---|---|---|---|
| cir-ITCH | ESCC | Low | cir-ITCH-miR-7/miR-17/miR-214-ITCH-Wnt signaling | Reduces cell viability and arrests proliferation in ESCC cells | [67] |
| Colorectal cancer | Low | cir-ITCH-Wnt signaling | Plays an anti-tumor role | [78] | |
| HCC | Low | Not mentioned | Has an inhibitory effect on HCC, and associates with survival of HCC | [112] | |
| hsa_circ_006793 | ESCC | High | Not mentioned | Correlates with tumor differentiation and TNM stage; promotes proliferation and migration of ESCC cell | [68] |
| circPVT1 | Gastric cancer | High | circPVT1-miR-125-E2F2 | An independent prognostic factors for overall survival and disease free survival in patients with gastric cancer; affects proliferation of gastric cancer cells | [24] |
| ciRS-7 (CDR1as) | Gastric cancer | High | ciRS-7-miR-7-PTEN/PI3K/AKT pathway | An independent risk factor of overall survival; Correlates with a more aggressive oncogenic phenotype | [73] |
| Colorectal cancer | High | ciRS-7-miR-7-EGFR/RAF1/MAPK pathway | An independent risk factor for overall survival with tumor stimulative effect | [79] | |
| HCC | high | ciRS-7-miR-7-EGFR or PI3K/AKT/mTOR pathway | An independent risk factor of hepatic microvascular invasion; correlates with the proliferation of hepatocellular carcinoma cells and the deterioration of HCC | [83,84] | |
| hsa_circ_0001895 | Gastric cancer | Low | Not mentioned | Associates with cell differentiation, Borrmann type, and tissue CEA expression; has a better sensitivity and specificity than the commonly used biomarkers of gastric cancer | [74] |
| circLARP4 | Gastric cancer | Low | circLARP4-miR-424-LATS1-YAP pathway | An independent prognostic marker for overall survival of gastric cancer patients as well as the patients with chemotherapy; inhibits DNA synthesis, cell proliferation and invasion; correlates with tumor size and lymphatic metastasis | [75] |
| hsa_circ_0000745 | Gastric cancer | Low | hsa_circ_0000745-miRNAs | Associates with tumor differentiation; has higher sensitivity and specificity than serum CEA levels | [76] |
| hsa_circ_000984 | Colorectal cancer | High | hsa_circ_000984-miR-106b-CDK6 | Promotes colorectal cancer cell proliferation, migration, invasion and tumor formation; correlates with advanced colorectal cancer | [81] |
| hsa_circ_001569 | Colorectal cancer | High | hsa_circ_001569-miR-145-E2F5/BAG4/FMNL2 | Promotes colorectal cancer cell proliferation and invasion | [82] |
| circCCDC66 | Colorectal cancer | High | circCCDC66-miRNAs-oncogenes | Promotes colorectal cancer cell proliferation, migration, invasion, and anchorage-independent growth; associates with poor prognosis | [22] |
| circHIPK3 | Colorectal cancer | High | c-Myb-circHIPK3-miR-7-FAK, IGF1R, EGFR, YY1 | Positively correlated with metastasis and advanced clinical stage; an independent prognostic factor of poor overall survival in colorectal cancer | [80] |
| circMTO1 | HCC | Low | circMTO1-miR-9-p21 | Suppresses hepatocellular carcinoma cell proliferation and invasion; associates with survival of HCC | [26] |
| hsa_circ_0004018 | HCC | Low | hsa_circ_0004018-miR-30e-5p/miR-626-MYC | Correlates with serum AFP level, tumor diameters, differentiation, BCLC stage and TNM stage; HCC-stage-specific expression features in diverse chronic liver diseases | [85] |
| circZKSCAN1 | HCC | Low | circZKSCAN1-miRNA-Mrna | Associates with tumor numbers, cirrhosis, vascular invasion, or microscopic vascular invasion; inhibits growth, migration, and invasion of HCC | [86] |
| cSMARCA5 | HCC | Low | cSMARCA5-miR-17-3p/miR-181b-5p-TIMP3 | An independent risk factor for overall survival and relapse-free survival after hepatectomy; inhibits the proliferation and migration of hepatocellular carcinoma cells | [87] |
| circRNA_100338 | HCC | High | circRNA_100338-miR-141-3p | Correlates with a low cumulative survival rate and metastatic progression in HCC patients with hepatitis B | [88] |
| circARSP91 | HCC | Low | AR-ADAR1-CircARSP91 | Suppresses tumor growth | [89] |