In this study, we herein examined the effects of the exosomes secreted from a stable hepatocellular carcinoma (HCC) cell line (HCC-exosomes) on the lumen formation of human umbilical vein endothelial cells(HUVECs). The uptake of HCC-exosomes by HUVECs and lumen formation by the HUVECs that included the exosomes were observed. The degree of lumen formation of HUVECs was dependent on the number of the HCC-exosomes. HCC-exosomes expressed a stress-induced heat shock protein associated with angiogenesis through the vascular endothelial growth factor(VEGF)receptor. In addition, the exosomes contained several microRNAs (miRNAs)reported to exist in the serum of HCC patients. The changes in the expression levels of miRNAs associated with angiogenesis were detected in the HUVECs treated with HCC-exosomes. Moreover, the abilities of the exosomes maintained after the treatment of cryopreservation. These results suggest that the HCC-exosomes play an important role in the angiogenesis. Further studies on the function of HCC-exosomes may provide a new target for HCC treatment.
