Fig. 5

Exosomal miRNAs from BMSCs promote metastasis by STAT3 driven EMT. C57BL/6 mice were subcutaneously injected with LLC-RFP with or without BMSCs. The red fluorescent protein positive LLC cells were collected from the tumor sites by flow cytometry cell sorting and subjected to RNA sequencing analysis. Timeline of experimental protocol was shown. a The upregulated genes were enriched in the JAK-STAT pathway. Clustering was performed on differentially expressed mRNAs between LLC cells collected from mice that received co-injection of BMSCs and LLC or LLC injection alone. Columns represent individual samples and rows represent each gene. Red and green reflect high and low expression levels, respectively. FPKM for STAT3 transcripts obtained by RNA-Seq was shown in histogram. b Protein expression of STAT3, p-STAT3 were measured by Western blot analysis. Cells were treated with normoxic BMSC-secreted exosomes or hypoxic BMSC-secreted exosomes. β-actin was used as the internal control. c Cell invasion was measured by transwell assay. The increased invasion capability induced by hypoxic BMSC-secreted exosomes was reversed by stat3 inhibitor stattics. Magnification, 100×. d Expression of Snail and Vimentin was measured by quantitative real-time PCR. Cells were treated with hypoxic BMSC-secreted exosomes with or without stat3 inhibitor stattics. Experiments were performed in triplicate.*P < 0.05. e Expression of stat3 measured by western blot. The miR-193a-3p inhibitor, miR-210-3p inhibitor and miR-5100 inhibitor could reverse the enhanced expression of phosphorylated STAT3 induced by exosomes released from hypoxia