Blue LED promotes the chemosensitivity of human hepatoma to Sorafenib by inducing DNA damage

Background: Phototherapies based on sunlight, infrared, ultraviolet, visible, and laser-based treatments present advantages like high curative effects, small invasion, and negligible adverse reactions in cancer treatment. We aimed to explore the potential therapeutic effects of blue light emitting diode (LED) in human hepatoma cells and decipher the underlying cellular and molecular mechanisms. Methods: Wound healing and transwell assays were employed to probe the inhibition of the invasion and migration of hepatocellular carcinoma cells in the presence of blue LED. The sphere-forming test was used to evaluate the effect of LED blue light irradiation on cancer stem cell properties. Immunofluorescence and western blotting were used to detect the changes in gamma-H2AX. The Cell Counting Kit-8 assay, 5-ethynyl-2 '-deoxyuridine staining, and colony formation assay were used to detect the combined effect of blue LED and sorafenib on cell proliferation inhibition. Results: We demonstrated that the irradiation of blue LED light in hepatoma cells could lead to cell proliferation reduction along with the increase of cell apoptosis. Simultaneously, blue LED irradiation also markedly suppressed the migration and invasion ability of human hepatoma cells. Sphere formation analysis further revealed the decreased cancer stemness of hepatoma cells upon blue LED irradiation. Mechanistically, blue LED irradiation significantly promoted the expression of the phosphorylation of the core histone protein H2AX (gamma-H2AX), a sensitive molecular marker of DNA damage. In addition, we found that the combined treatment of blue LED irradiation and sorafenib increased cancer cell sensitivity to sorafenib. Conclusion: Collectively, we demonstrated that blue LED irradiation exhibited anti-tumor effects on liver cancer cells by inducing DNA damage and could enhance chemosensitivity of cancer cells, which represents a potential approach for human hepatoma treatment.