The light emitting diodes (LEDs) irradiation has been demonstrated to be potential therapeutic strategies for
several diseases. However, the blue LED effects remain largely unknown in colorectal cancer (CRC), which is a
major cause of morbidity and mortality throughout the world. In this study, we determined the effects of blue
LED irradiation, the maximal light emission at 470 nm in wavelength, in human CRC cell lines SW620 and HT29.
The cells were irradiated with blue LED light for 0 J/cm2
, 72 J/cm2
, 144 J/cm2
, 216 J/cm2 and 288 J/cm2 respectively. We found that irradiation with blue LED light induced a marked decrease of live cells and an increase
of dead cells. Additionally, lower cell proliferation and a remarkably increase of cell apoptosis were observed in
blue LED-irradiated cells as compared with non-irradiated control group. The cell migration was significantly
inhibited by blue LED irradiation 24, 48 and 72 h later compared with non-treated group. Blue LED-treated CRC
cells further displayed a remarkably inhibition of EMT process in CRC cells. Finally, we found the accumulation
of ROS production and DNA damage were induced by blue LED irradiation. These results indicated that blue LED
irradiation inhibits CRC cell proliferation, migration and EMT process as well as induces cell apoptosis, which
may result from increased ROS accumulation and induction of DNA damage.