Fig. 3

The contribution of TAM-derived exosomes in cancer progression and metastasis. TAM-derived exosomes contribute to the malignant behavior of cancer cells through ncRNAs such as miRNA, CircRNA, and LncRNA. For instance, miRNA facilitates cancer cell proliferation and metastasis by targeting mRNA to regulate gene expression, while CircRNA functions as a miRNA sponge that modulates gene expression by interacting with miRNA. Moreover, LncRNA LINC01232 facilitates the evasion of cancer cells from CD8 + T cell-mediated immunity attack through degrading and downregulating MHC-I. Furthermore, PD-L1 within exosomes from both TAMs and tumor cells leads to immune suppression by limiting CD8 + T cell activation and proliferation. TAM-derived exosomes also alter the differentiation of naïve CD4 + T cells and the balance of CD4 + T cell subsets, thus aggravating immune suppression. Additionally, TAM-derived exosomes promote the formation of the vascular system through various means, including enhancing vasculogenic mimicry and angiogenesis. ncRNAs non-coding RNA, let-7a lethal-7a, C15orf41 chromosome 15 open reading frame 41, E2F3 E2F transcription factor 3, NBR1 neighbor of breast cancer 1 gene, TCR T cell antigen receptor, PD-L1 programmed death-ligand 1, PD-1 programmed cell death protein 1, Treg Regulatory T cell, Th1 T Helper 1 cell, TIMP2 tissue inhibitor of metal protease 2