COULD LOW-POWER INFRARED LASER MODULATE P53 PROTEIN AGGREGATION IN HUMAN BREAST CANCER CELLS?

Lasers produce radiation characterized by coherence, collimation, and high energy density. These characteristics are critical for photobiomodulation effects such as ATP production, DNA and RNA synthesis, cell proliferation, and wound healing. The application of low-power lasers in cancer patients is debated due to their cellular effects, with controversial results. Breast cancer is a leading cause of cancer in women globally often associated with mutations in the p53 gene, which disrupt cell cycle control, and increase cell proliferation and aggressiveness. These mutations are correlated with p53 aggregation and gain of oncogenic function. Due to tumor complexity, new strategies, and approaches are needed to treat these conditions. This study aims to evaluate the effects of a low-power infrared laser on p53 protein aggregation in MCF-7 and MDA-MB-231 breast tumor cells. MCF-7 and MDA-MB-231 cells were irradiated with a low-power infrared laser (808 nm; 10, 15, and 20 J/cm²), with non-irradiated cells as control. Post-irradiation, cells were incubated for 24 and 48 hours at 37 °C, 5% CO₂. Cell extracts were prepared, and protein concentrations were determined using the Lowry protein assay. Protein aggregation was assessed using a dot blot assay with p53 and A11 (antioligomers) antibodies and visualized with the Chemidoc system. Preliminary data suggest that the low-power infrared laser enhanced wild-type p53 protein content in MCF-7 cells at 24 hours at all fluences. This effect was observed at 48 hours only in 20 J/cm².  In MDA-MB-231 at 24 hours, mutated p53 protein content was reduced at 10 J/cm² and enhanced at 15 J/cm². At 48 hours, it was enhanced at 15, and 20 J/cm². At all fluences evaluated, the total oligomer content was enhanced only in MDA-MB-231 at 24 hours. Further RT-qPCR data are needed to assess p53 expression and assays for proliferation, migration, viability, and drug resistance to understand cell dynamics. Our findings suggest that low-power infrared laser potentially modulates p53 protein expression and aggregation in both cell models evaluated. However, additional studies are required to fully understand the implications on expression, aggregation modulation, and cellular dynamics.