Effect of Photobiomodulation Therapy in an In vitro Model of Lung Adenocarcinoma

Abstract

Aims: To evaluate the dosimetric parameters and biological effects of photobiomodulation in an in vitro model of urethane-induced lung adenocarcinoma. Specifically, to quantify inflammatory mediators (IL-6, IL-8, IL-10, IL-1β, and IFN-γ) and assess the functional activity of BEAS-2B cells incubated with urethane and irradiated with low-level laser therapy (LLLT) at two energy densities (3 J and 7.5 J). Study Design: An experimental in vitro study using BEAS-2B bronchial epithelial cells exposed to urethane and treated with LLLT at 660 nm. Place and Duration of Study: Department of Medicine – Biophotonics, Universidade Nove de Julho, Campus Vergueiro, São Paulo, Brazil, between March 2020 and December 2022. Methodology: BEAS-2B cells were cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum, 1% glutamine, and 100 U/mL gentamicin. After 24 hours, the cells were incubated with urethane (375 μg/mL) for 1 hour and then irradiated with LLLT (3 J or 7.5 J, 660 nm). Supernatants were collected after 24 hours for cytokine quantification. Four experimental groups were established: (1) Control (untreated cells), (2) LLLT (cells irradiated without urethane exposure), (3) Urethane (cells treated with urethane only), and (4) Urethane+LLLT (urethane-treated cells irradiated with LLLT). Results: The Urethane group showed a significant increase in IL-1β, IL-6, and IL-8 levels and a decrease in IL-10 compared to the Control group. Conversely, the Urethane+LLLT group exhibited a reduction in IL-1β, IL-6, and IL-8 levels, as well as an increase in IL-10 and IFN-γ, compared to the Urethane group. Conclusion: Photobiomodulation demonstrated beneficial effects at both 3 J and 7.5 J, though the 3 J energy density provided the most pronounced anti-inflammatory response in urethane-exposed BEAS-2B cells. Further in vivo studies are required to validate these findings and explore the therapeutic potential of LLLT in lung cancer models.