uMSCs secrete many types of protective cytokines and MSCCM inhibits the proliferation of MRC-5 cells. A-D, Expression of the cytokines of HGF, EGF, KGF and VEGF measured in the control media and the conditioned medium of uMSCs. E, cell viability analyzed by CCK8 assay. The results were compared among control cells (Con), single-irradiated MRC-5 cells (IR), and irradiation + MSCCM treated MRC-5 cells (IR+MSCCM). Data are expressed as the mean ± SD (n=5). *p< 0.05, **p< 0.01.