Laser Light Is Capable of Inducing Proliferation of Carcinoma Cells in Culture: A Spectroscopic in Vitro Study

OBJECTIVE: The objective of this work was to evaluate the influence of time, treatment, and wavelength, through the assessment of the cellular viability with MTT, on the proliferation of H.Ep.2 cells subjected to laser irradiation or not (lambda685 and lambda830 nm) with the same energy density (4 J/cm2). BACKGROUND DATA: Although malignant lesions have been studied for some time, there is not yet a definitive cure. Mortality could be reduced if lesions were diagnosed on initial phases of development. MATERIALS AND METHODS: H.Ep.2 cells were cultured in flasks and maintained in DMEN medium (10% FBS, 1% L-glutamine, and 1% antibiotic solution). For irradiation, cells were kept in 24 wells of the 96-well plaques containing DMEM medium (5% FBS, 1% L-glutamine, and 1% antibiotic solution), irradiated with lasers at lambda685- and lambda830-nm wavelength, and stained at 0, 6, 12, 24, and 48 h after irradiation. RESULTS: There was significant differences when the three groups were compared (p = 0.0087). There was significant difference for both irradiated groups, lambda685 nm (p = 0.0202) and lambda830 nm (p = 0.0324). Time of irradiation significantly influenced only the lambda685-nm group (p = 0.04). The wavelength had a significant influence (p = 0.013). CONCLUSION: Time, treatment, and wavelength significantly influenced the proliferation process of H.Ep.2 cells.