RESUMO
This study was conducted to investigate the inhibitory effects of light-emitting diodes (LEDs) on exosome biogenesis and angiogenesis capacity in Ishikawa endometrial cancer cells. To this end, cells were exposed to different energy densities (fluences) of 4, 8, 16, 32, and 64 J/cm2 for 5 days (once every 24 h), and cell viability was determined using an MTT assay. Based on data from the MTT panel, cells were exposed to 4 and 16 J/cm2 for subsequent analyses. Exosome biogenesis was also monitored via monitoring the expression of CD63, ALIX, and Rab27a and b. The size and morphology of exosomes in the supernatant were measured using scanning electron microscopy (SEM), and dynamic light scattering (DLS). Using Transwell insert, the migration capacity of these cells was studied. The angiogenic effects of irradiated Ishikawa cell secretome at different fluences were monitored on human endothelial cells using in vitro tubulogenesis. Results indicated LED can reduce the viability of Ishikawa cells in a dose-dependent manner. According to our data, 4 and 64 J/cm2 groups exhibited minimum and maximum cytotoxic effects compared to the control cells. Data revealed a close proportional relationship between the power of laser and exosome average size compared to the non-treated control cells (p < 0.05). Real-time PCR analysis showed the suppression of Rab27b and up-regulation of Rab27a in irradiated cells exposed to 4 and 16 J/cm2 (p < 0.05). These effects were evident in the 16 J/cm2 group. Likewise, LED can inhibit the migration of Ishikawa cells in a dose-dependent manner (p < 0.05). Tubulogenesis activity of endothelial cells was suppressed after incubation with the secretome of irradiated Ishikawa cells (p < 0.05). These data showed tumoricidal properties of LED irradiation on human adenocarcinoma Ishikawa cells via the inhibition of exosome biogenesis and suppression of angiogenesis capacity.