Tumor-derived exosomal miR-934 induces macrophage M2 polarization to promote liver metastasis of colorectal cancer.

BACKGROUND: Mounting evidence has demonstrated the vital importance of tumor-associated macrophages (TAMs) and exosomes in the formation of the premetastatic niche. However, the molecular mechanisms by which tumor-derived exosomal miRNAs interact with TAMs underlying premetastatic niche formation and colorectal cancer liver metastasis (CRLM) remain largely unknown. METHODS: Transmission electron microscopy and differential ultracentrifugation were used to verify the existence of exosomes. In viv...