Blue Light Inhibits Proliferation of Metastatic Cancer Cells by Regulating Translational Initiation: A Synergistic...

The aim of this study was to examine the inhibitory effect of blue light (BL) on the proliferation of metastatic cancer cells and synergistic properties with chemo-drugs. BL significantly inhibited the proliferation of B cell lymphoma (A20 and RAMOS) cells in a dose-dependent manner. Anti-proliferative effect of BL irradiation was identified to be associated with the inhibition of proliferating-cell nuclear antigen expression and cell cycle by decreasing S-phase cells. Consistent with its inhibitory effects, BL irradiation at 20 J/cm² daily for 10 days inhibited metastasis of cancer cells which were distributed and invaded to other organs including bone marrow, liver, kidney, etc., and induced paraplegia, thereby leading to an increased survival rate of tumor-bearing mice. Anti-proliferative activity of BL was expanded in solid tumor cells including pancreatic carcinoma (Mia PaCa-2, PANC-1), lung carcinoma A549 and colorectal carcinoma HCT116 cells. Additionally, combination with chemo-drugs such as 5-FU and gemcitabine resulted in an increase in the anti-proliferative activity after BL irradiation accompanied by regulating mRNA translational process via inhibition of p70S6K, 4EBP-1 and eIF4E phosphorylation during cellular proliferation. These results indicate the anti-metastatic and photo-biogoverning abilities of BL irradiation as a potent therapeutic potential for repressing the progression of tumor cells.