Effects of low-level laser irradiation on VEGF expression of melanoma cell lines

Abstract

Impact of low-level laser irradiation on tumor cell lines remains controversial. Vascular endothelial growth factor (VEGF) is a key molecule to form new blood vessels, which contribute for cancer development and growth. The aim of this study was to evaluate the effects of different light fluences on human melanoma SKMEL 37 cells and murine melanoma B16F10 cells using a near infrared laser (λ= 780 nm) with output power of 40 mW delivering energies of 1.2, 3.6 and 6 J (fluences of 30, 90 and 150 J/cm2, respectively). The cell lines were irradiated 24 h after they were seeded in a 96-well plate at a density of 5x103 cells per well, in triplicate at three different days. Following irradiation, both cell line supernatants were stored in Eppendorf tubes at - 20°C until VEGF-A expression measurement. Specific ELISA kits were used according to cell line (murine or human). Samples and standard solutions were added in a 96-well plate antibody-coated and incuba ted over night at 4°C. Reagent dilution and set time followed fabricant instructions. The stop solution was added and the absorbance was read in a microplate reader at 450 nm. Results showed a non-statistically significant difference among treated and control groups for both cell lines. These findings indicate that irradiation with near infrared laser does not influence VEGF expression on melanoma cell lines regardless the fluence used and should be tested to prevent cancer growth in preclinical assays.