Fig. 4

Exo-miR-15b-3p high expression in GC patient serum as a GC diagnosis and prognosis biomarker. a Representative electron microscopy micrographs of SGC-7901, BGC-823 and GES-1 cell conditioning medium secreted exosomes, as well as control and GC patient serum secreted exosomes. Scale bar, 100 nm. b Nano Sight particle-tracking analysis to determine exosome size distribution and number. c Levels of exosomal markers, TSG101, CD63 and CD9, of cells and serum derived exosomes determined using western blotting analysis. d Relative expressions of Exo-miR-15b-3p in conditioned medium of BGC-823, SGC-7901 and GES-1 cells. e Relative exosomal miR-15b-3p levels in GC patients and non-GC normal volunteer (n = 108) serum. f The sensitivity and specificity of serum Exo-miR-15b-3p for GC prediction was evaluated through Receiver-operating characteristic (ROC) curve analysis. g The correlation between serum Exo-miR-15b-3p expression and overall survival of the 108 GC patients determined using Kaplan–Meier analysis. The cutoff used was the median. Mean ± SEM of the results are presented