CD133+ liver cancer stem cells modulate radioresistance in human hepatocellular carcinoma

CD133 is a cancer stem-cell (CSC) marker associated with radioresistance and chemoresistance in various cancers. In the present study, CD133-expressing liver cancer cells following radiation exposure showed higher activation of MAPK/PI3K signaling pathway and reduction in reactive oxygen species levels compared to CD133− cells. The in vivo study with a xenograft model showed increased tumor formation in irradiated CD133+ cell-injected nude mice compared to the CD133− group, suggesting that CD133 contributes to radioresistance in HCC. Therefore, CD133-expressing liver cancer cells have anti-apoptotic and radioresistance properties that may be useful to improve anti-cancer treatments, including chemotherapy/radiotherapy of HCC.

► CD133+ cells activate cell-cycle-related proteins after irradiation.
► The activation of cell-cycle-related proteins regulate G2/M cell-cycle arrest.
► CD133+ cells show anti-apoptotic and proliferative activities after irradiation.
► The proliferation of CD133+ cells is enhanced via activation of ERK/MAPK pathway.
► Liver cancer cells expressing CD133 are associated with radioresistance.