Cellular senescence is an irreversible state of cell cycle arrest, thus being characterized by decreased cell proliferation and increased nucleus area, often acting as a tumor suppressor program. Photobiomodulation (PBM) has been used in several conditions to increase the mitochondrial response, promoting nuclear changes and cell proliferation. However, the effects of PBM on cells are still unclear.

To verify the efficacy of photobiomodulation on cell senescence processes.

We utilized A172 glioblastoma cells transduced with H2B-mCherry by lentivirus to nuclear tagging. Treatment was done with GaAIAs Laser (850nm). Cells were divided by intensity into the following groups: C= Control, L1= 1J/cm², L2= 2.2J/cm², L3= 3J/cm², L9= 9J/cm², L15= 15J/cm², L21= 21J/cm², nuclear evaluation was performed at experimental times (0h, 24h, 48h and 72h). For data analysis, two-way ANOVA with the Tukey post hoc test was used. Differences were significant when p<0.05.

PBM on intensities of 1J/cm², 2.2J/cm², 3J/cm², 9J/cm² e 15J/cm² showed a lower increase at the nuclear size when compared with time 0h and 72h in the control group. All intensities (1, 2.2, 3, 9, 15, and 21 J/cm²) promoted cellular proliferation after 72 hours, while 15J/cm² presented an accentuated increase compared to groups L1, L2.2, and L3.

PBM enhanced cellular proliferation while causing a reduced nuclear increase in glioblastoma cells.

In this study, we found that the laser decreased the cellular senescence state from the evaluation of the morphological parameters, thus increasing cell proliferation and decreasing the nuclear area; therefore, it is an important therapeutic tool against the cellular aging process.