Human amniotic epithelial cells exert anti-cancer effects through
secretion of immunomodulatory exosomes
Abstract
We identified here mechanism by which hAEC exert their anti-cancer
effects. We showed that vaccination with live hAEC conferred effective
protection against murine colon cancer and melanoma but not against
breast cancer in orthotopic cancer cell inoculation model. hAEC induced
strong cross-reactive antibody response to CT26 cells, but not against
B16F10 and 4T1 cells. Neither heterotopic injection of tumor cells in
AEC-vaccinated mice nor vaccination with hAEC lysate conferred
protection against melanoma or colon cancer. Nanosized AEC-derived
exosomes (ADE) induced apoptosis in CT26 cells and inhibited their
proliferation. Co-administration of ADE with tumor cells substantially
inhibited tumor development and increased CTL responses in vaccinated
mice. Our results clearly showed that it is ADE but not the
cross-reactive immune responses against tumor cells that mediate
inhibitory effects of hAEC on cancer development. Our results
highlighted the potential anti-cancer effects of exosomes derived from
hAEC.