The pulse light mode enhances the effect of photobiomodulation on B16F10 melanoma cells through autophagy pathway.

Photobiomodulation (PBM) is the use of low irradiance light of specific wavelengths to generate physiological changes and therapeutic effects. However, there are few studies on the effects of PBM of different LED light modes on cells. Here, we investigated the difference of influence between continuous wave (CW) and pulse-PBM on B16F10 melanoma cells. Our results suggested that the pulse mode had a more significant PBM than the CW mode on B16F10 melanoma cells. Our study confirmed that ROS and Ca2+ levels in B16F10 melanoma cells treated with pulse-PBM were significantly higher than those in the control and CW-PBM groups. One mechanism that causes the difference in CW and pulse-PBM action is that pulse-PBM activates autophagy of melanoma cells through the ROS/OPN3/Ca2+ signaling pathway, and excessive autophagy activation inhibits proliferation and apoptosis of melanoma cells. Autophagy may be one of the reasons for the difference between pulse- and CW-PBM on melanoma cells. More importantly, melanoma cells responded to brief PBM pulses by increasing intracellular Ca2+ levels.

Comparative transcriptome analysis of gene expression patterns on B16F10 melanoma cells under Photobiomodulation of different light modes.

Cutaneous melanoma is one of the aggressive cancers. Recent studies have shown that Photobiomodulation (PBM) can inhibit the proliferation of melanoma cells. However, it is not clear that the effect of PBM light mode on the inhibition of melanoma cells. Herein, we investigated the difference of influence between continuous wave (CW) and Pulse PBM on B16F10 melanoma cells. Our results suggested that Pulse mode had a more significant inhibition on the viability of B16F10 melanoma cells than CW mode under the PBM light parameter of wavelength, dose, and average irradiance at 457 nm, 1.14 J/cm2, and 0.19 mW/cm2. Besides, we revealed the differentially expressed genes of B16F10 melanoma cells under the various treatments of PBM light mode (not PBM treatment, CW mode, and Pulse mode) by RNA sequencing. Together, our data suggested that Pulse-PBM can improve the effect of PBM on cells significantly and there may be different molecular mechanisms between Pulse and CW mode including anti-proliferative and cell necrosis. The study shed new light on investigating the molecular mechanisms of various PBM light modes on B16F10 melanoma cells.