MiRNA-142-3p increases radiosensitivity in human umbilical cord blood mononuclear cells by inhibiting the expression of CD133.

This study is to explore the molecular regulation mechanism of CD133 which is associated with malignancy and poor prognosis of blood system diseases. CD133+HUCB-MNC (human umbilical cord blood mononuclear cells) and CD133-HUCB-MNC were isolated and amplificated from umbilical cord blood, and then were exposed to different doses of radiation and subjected to a clonogenic assay. CCK-8 kit was used to detect cell viability, Annexin V-FITC/PI cell apoptosis detection kit was used for the detection of apoptotic cells and the BrdU assay was performed by flow cytometry. The expression of protein was analyzed by western blots. The profile of miRNA expression in response to radiation was examined and validated by RT-PCR. miR-142-3p inhibited the expression of CD133 in umbilical cord blood mononuclear cells to increase radiosensitivity. CD133+HUCB-MNC cells were more radioresistant compared with CD133-HUCB-MNC cells. CD133+HUCB-MNC cells showed higher p-AKT and p-ERK levels after radiation. And miR-142-3p acted on 3'UTR of CD133 mRNA to inhibit CD133 expression. Moreover, miRNA-142-3p mimic increased radiosensitivity in CD133+HUCB-MNC cells. Our results elucidated a novel regulation pathway in hematopoietic stem cells and suggested a potential therapeutic approach for blood system diseases therapy.