Tumor-derived exosomal miR-3157-3p promotes angiogenesis, vascular permeability and metastasis by targeting TIMP/KLF2 in non-small cell lung cancer

Metastasis is the main cause of death in patients with advanced lung cancer. The exosomes released by cancer cells create tumor microenvironment, and then accelerate tumor metastasis. Cancer-derived exosomes are considered to be the main driving force for metastasis niche formation at foreign sites, but the mechanism in Non-small cell lung carcinoma (NSCLC) is unclear. In metastatic NSCLC patients, the expression level of miR-3157-3p in circulating exosomes was significantly higher than that of non-metastatic NSCLC patients. Here, we found that miR-3157-3p can be transferred from NSCLC cells to vascular endothelial cells through exosomes. Our work indicates that exosome miR-3157-3p is involved in the formation of pre-metastatic niche formation before tumor metastasis and may be used as a blood-based biomarker for NSCLC metastasis. Exosome miR-3157-3p has regulated the expression of VEGF/MMP2/MMP9 and occludin in endothelial cells by targeting TIMP/KLF2, thereby promoted angiogenesis and increased vascular permeability. In addition, exosome miR-3157-3p promoted the metastasis of NSCLC in vivo.