RESUMO
Ultraviolet (UV) radiation is considered to be a potent cell-damaging agent in various cell lineages; however, the effect of UV lightemitting diode (LED) irradiation on human cells remains unclear. The aim of the present study was to examine the effect of UV LED irradiation emitting at 280 nm on cultured HL60 human leukemia cells, and to explore the underlying mechanisms. HL60 cells were irradiated with UV LED (8, 15, 30 and 60 J/m2) and incubated for 2 h after irradiation. The rates of cell proliferation and apoptosis, the cell cycle profiles and the mRNA expression of Bcell lymphoma 2 (Bcl2) were detected using cell counting kit8, multicaspase assays, propidium iodide staining and reverse transcriptionquantitative polymerase chain reaction, respectively. The results showed that UV LED irradiation (860 J/m2) inhibited the proliferation of HL60 cells in a dosedependent manner. UV LED at 830 J/m2 induced dosedependent apoptosis and G0/G1 cell cycle arrest, and inhibited the expression of Bcl2 mRNA, while UV LED at 60 J/m2 induced necrosis. In conclusion, 280 nm UV LED irradiation inhibits proliferation and induces apoptosis and necrosis in cultured HL60 cells. In addition, the cell cycle arrest at the G0/G1 phase and the downregulation of Bcl2 mRNA expression were shown to be involved in UV LED-induced apoptosis.