Table 1 The role of exosomal miRNAs in breast cancer in the PMN

Breast cancer cell

miRNA-9

miRNA-181a

Upregulate in MDSCs, target SOCS3 and PIAS3

[56]

Astrocyte

miRNA-19a

Induce CCL2 upregulation, increase brain metastasis

[87]

Breast cancer cell

miRNA-105

Induce vascular permeability

[71]

Breast cancer cell

miRNA-122

Modifying glucose utilization by recipient PMN cells

[105]

Breast cancer cell

miRNA-200

Suppresses EMT, which enhances lung metastasis and colonization

[88]

nSMase2

miRNA-210

Enhanced angiogenesis

[69]

XIST_low breast cancer cell

miRNA-503

Trigger M1-M2 polarization of microglia (enhancing their PD-L1 expression to suppress local immunity)

[106]

Breast cancer cell

miRNA-21

Promote formation of PMN

[27]

CAF

miRNA-18b

Promote nuclear Snail ectopic activation inducing EMT

[107]

Breast cancer cell

miRNA-200b-3p

Regulate CCL2 expression in the lung

[50]

MSC

miRNA-100

Affect the vascular behaviour of endothelial cells

[108]