Expression Level of miR-9 in Exosomes Derived from Ovarian Epithelial Carcinoma Cells and the Effects of Exosome Treatment on VEGF Expression in Human Umbilical Vein Endothelial Cells

Aims: Exosomes are considered as a protective and enriched source of shuttle microRNAs. However, the precise biological mechanism of exosomal microRNAs in recipient cells remains to be further clarified. The aim of this study waz to investigate Expression level of miR-9 in exosomes derived from ovarian epithelial carcinoma cells and the effects of exosome treatment on Vascular Endothelial Growth Factor )VEGF( expression in human umbilical vein endothelial cells.
Material and Exosomes were purified from the conditioned medium of ovarian epithelial carcinoma cells. Exosome size and morphology were examined by a scanning electron microscope. Purified exosomes were labeled with PKH26 red fluorescent labeling kit, then labeled exosomes were incubated with human umbilical vein endothelial cells (HUVECs) for 12h at 37°C, and the cellular uptake was monitored using an inverted fluorescence microscope. Expression levels of miR-9 and VEGF were measured by real-time PCR. Paired t-test was used for data analysis.
Findings: The purified MSCs-derived exosomes had a spherical shape with a diameter between 50 to 100nm. PKH26-labeled exosomes can be taken up by SKOV3 tumor cells with high efficiency. The expression levels of miR-9 in both ovarian tumor cells and their exosomes. Exosomes derived from ovarian tumor cells caused increased expression of VEGF in exosome-treated endothelial cells.
Exosomes derived from ovarian tumor cells led to increased expression of VEGF in endothelial cells. As miR-9 was enriched in both ovarian tumor cells and their exosomes, it seems that exosomal transfer of miR-9 may affect the expression of VEGF in endothelial cells during tumor angiogenesis.