Table 1.
Representative circular RNAs targeting immune cells
| CircRNA | Immune cell | Expression | Targeted miRNA | Downstream target | Cancer type | Immune-related functions | Clinical correlation | Reference |
|---|---|---|---|---|---|---|---|---|
| circ-LAMP1 | T cells | Up-regulated | MiR-615-5p | DDR2 | T-cell lymphoblastic lymphoma | Inhibiting cell apoptosis in T-LBL cells | / | [49] |
| circ-NT5C2 | T cells | Up-regulated | MiR-448 | IDO1 | Osteosarcoma | Enhancing the CD8+ T cell response | / | [45] |
| hsa_circ_0005519 | T cells | / | Hsa-let-7a-5p | IL-13 and IL-6 | / | Activating T cell related immune response | / | [42] |
| hsa_circ_0012919 | T cells | / | MiR-125a-3p | / | / | Mediating activation, proliferation and differentiation of T cells and B cells and immune response | / | [43] |
| circRNA100783 | T cells | / | / | / | / | MediatingCD28-related CD8(+) T cell ageing and global immune senescence | / | [47] |
| hsa_circ_0064428 | B cells | Down-regulated in patients with high tumor-infiltrating lymphocytes | Hsa-miR-7977, hsa-miR-4530, hsa-miR-4692, hsa-miR-4514 and hsa-miR-4645 | / | Hepatocellular carcinoma | Upregulating TIL frequency | Tumor size, metastasis, overall survival | [61] |
| circ_0000977 | NKs | Up-regulated | MiR-153 | HI1FA, ADAM10 | Pancreatic cancer | Inhibiting NK cell lysis, resulting immune escape of pancreatic cancer cells | / | [69] |
| circARSP91 | NKs | Down-regulated | / | / | Hepatocellular carcinoma | Strengthening the cytotoxicity of NK cells, enhancing innate immune surveillance | Overall survival | [65] |
| circTRIM33–12 | NKs | Down-regulated | MiR-191 | TET1,5hmC | Hepatocellular carcinoma | Enhancing immune response, preventing cancer progression | Overall survival | [66] |
| hsa_circ_0008433 | NKs | / | Hsa-miR-181c-5p and hsa-miR-181b-5p | MMP2 | / | Inducing NK cells to attack arterial elastic fibers and remodel vessels | / | [63, 64] |
| circ790 | Macrophages | Down-regulated | / | IL-6, IL-1β and TNF-α | / | Modulating the secretion of specific cytokines and mediates immune response | / | [92] |
| hcircRasGEF1B | Macrophages | Down-regulated | / | ICAM-1 | / | Promoting of LPS response and regulating macrophage polarization | / | [93] |
| circHECTD1 | Macrophages | / | / | / | / | Regulating macrophage polarization | / | [96] |
| circC3P1 | MDSCs | Down-regulated | MiR-21 | PTEN | Kidney cancer | Downregulating the protein levels of PTEN, restraining the PI3K/AKT and NF‐κB pathways | / | [72] |
| circSLC8A1 | MDSCs | Down-regulated | MiR-130b/miR-494 | PTEN, ARG1 and iNOS | Bladder cancer | Downregulating the protein levels of PTEN | / | [71] |
| circ-MTO1 | MDSCs | Down-regulated | MiR-17-5p | ROS | Prostate cancer | Inhibiting the immunosuppressive function | / | [40] |
| cricFOREIGN | DCs | / | / | / | / | Activating DCs directly and indirectly activating CD4+ follicular T-helper (Tfh) cells and CD8+ T cells | / | [50] |
| f-circPR | Granulocytes | Up-regulated | / | / | Acute promyelocytic leukemia | Promoting tumorigenesis, tumor cell proliferation and cell transformation | / | [22] |
| f-circM9 | Granulocytes | Up-regulated | / | / | Acute promyelocytic leukemia | Promoting tumorigenesis, tumor cell proliferation, cell transformation and resistance to arsenic trioxide | / | [22] |
| circ-HIPK2 | Granulocytes | Up-regulated | MiR-124-3p | CEBPA | Acute promyelocytic leukemia | Affecting all-trans retinoic acid-induced differentiation of | / | [90] |