Figure 2. Isolation and identification of MSCs and MSC-derived exosomes. (A) Expression of BMMSC surface markers determined by flow cytometry. (B) TEM image for MSC-derived exosomes, scale bar = 100 nm. (C) Particle distribution of MSC-derived exosomes analyzed by Zetasizer Nano ZS. (D) Expression of exosome markers measured by western blot analysis. (E) miR-106a-5p expression in MSCs in response to miR-106a-5p mimic/ AMO-miR-106a-5p transfection as detected by qRT-PCR. n = 6, *p<0.05. (F) Exosomes in MSCs were isolated, and miR-106a-5p expression was detected using qRT-PCR. n = 6, *p<0.05. (G) TNBC cell lines BT549 and MDA-MB-231 cells were incubated with MSCs in response to miR-106a-5p mimic/ AMO-miR-106a-5p transfection, and miR-106a-5p expression was determined by qRT-PCR. n = 6, *p<0.05. The above measurement data were expressed as mean ± standard deviation. Data among multiple groups were analyzed by one-way ANOVA, followed by a Tukey post hoc test. The experiment was repeated in triplicate.