Fig. 7: Exosomal circUBE2Q2 regulates the STAT3 signaling pathway and EMT in vitro and promotes metastasis in vivo.

A Expression level of circUBE2Q2 in the plasma exosomes from normal people (n = 30) and GC patients (n = 60) determined via qRT-PCR. B Existence and morphology of exosomes purified from MKN-45 cell medium (exosome-free FBS) determined by a transmission electron microscope (TEM) and exosomal markers CD63 and CD81 via western blottings. C The existence of the red exosome signals in the cytoplasm of MKN-45 cells, scale bar = 20 μm. D The red signals of circUBE2Q2 in the cytoplasm of GFP-labeled MKN-45 cells, scale bar = 20 μm. E Higher circUBE2Q2 expression in exosomes purified from cirUBE2Q2-overexpressing MKN-45 cells detected by qRT-PCR. F Protein levels of STAT3, p-STAT3, Twist, Snail, Slug, N-Cadherin, and E-Cadherin detected by western blottings. G Peritoneal metastasis in MKN-45 cells treated with NC or circUBE2Q2 OV exosomes measured by luciferase intensities. H The cancerous node size characterized by the liver tissues for H&E staining. Liver index = liver weight/body weight. Data are expressed as the mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001.