Table 1.
Role of MDSC-miRs in tumorigenesis and response to cancer therapies.
| miR | Cells | Expression | Target genes/Pathways | Phenotype | References |
|---|---|---|---|---|---|
| miR-125a~ 99b~let-7e |
Monocytes | ↑ | TRIB; SOCS1 | Immunosuppressive properties mediated by STAT3 activation | (36) |
| miR-125a and let-7e |
Monocytes | ↑ | TLR4; CD14; IRAK1 | ↓ Anti-inflammatory activity and cyto/chemokines | (17) |
| miR-125b | Macrophages | ↑ | IRF4 | Acquisition of M1 phenotype | (37) |
| T cells | ↑ | IFNG; IL10RA; IL2RB; PRDM1 | Suppression of CD4+ T cell differentiation | (37) | |
| T cells | ↑ | CD107a; TNFA; IFNG | Inhibition of γδ T cell activation | (37) | |
| miR-100 | Tregs | ↑ | SMAD2 | ↓ Treg differentiation and ↑ plasticity | (38) |
| miR-146b | Macrophages | ↑ | IRF5 | ↓ M1 macrophage and inflammation | (39) |
| miR-146a | Monocytes | ↓ | TRAF6; IRAK1 | ↑ chronic NFkB driving myeloid malignancy | (40, 41) |
| Breast cancer | ↓ | TRAF6/IRAK1 | ↑ NFkB activity and metastasis | (42) | |
| Endometrial cancer | ↑ | NIFK-AS1 | ↑ M2-like phenotype of TAMs | (43) | |
| Hepatocellular carcinoma | ↑ | STAT3 | Immunosuppression by ↑TGFβ, IL17, VEGF and ↓type I IFN | (44) | |
| Melanoma | ↑ | STAT1/IFNγ axis; PD-L1 | Melanoma migration, MDSC promotion and resistance to ICIs | (8, 45) | |
| MDSCs | ↑ | NFkB | ↓ NFkB-mediated inflammation | (46) | |
| T cells | ↑ | IFNγ and perforin | ↓ ICI-mediated irAEs severity | (47) | |
| miR-155 | Breast cancer | ↑ | SOCS1/SHIP1 | Activation of STAT3 signaling and pro-tumor inflammation | (48) |
| Myeloid cells | ↓ | C/EBP-β | Breast tumor growth by MDSC infiltration and TAM tolerance | (49, 50) | |
| MDSCs | ↓ | HIF-1α | ↑ MDSC recruitment and function, ↑ solid tumor growth | (51) | |
| MDSCs | ↑ | SHIP1 | ↑ STAT3 activation and expansion of functional MDSCs | (52) | |
| Colorectal cancer | ↑ | SOCS1 | ↑ MDSC activity and tumor growth | (53) | |
| T cells | ↑ | SHIP1 | ↑ IFNγ production, ↑ T cell-mediated antitumor immunity | (54) | |
| Melanoma | ↑ | ND | MDSC induction ↑ resistance to immunotherapy | (8) | |
| T cells | ↑ | T cell activation markers | ↑ T cell response | (55) | |
| T cells | ↑ | PRC2/Phf19 | ↑ cancer immunotherapy by ↑ CD8+ T cell function | (14) | |
| T cells | ↑ | TIM3 | Cytolytic activity of CD8+ T cells against HCC | (56) | |
| T cells | ↑ | ND | ↑ antitumor activity of CD8+ T cells | (57) |
ND, not defined; ↑, increased; ↓, decreased.