RESUMEN
Heat shock proteins [HSPs] are molecular chaperones involved in protein folding, stability and turnover, and due to their role in cancer progression, the effect of low power laser irradiation [LPLI] on the expression of HSP70 and HSP90 in Jurkat E6.1 T-lymphocyte leukemia [JELT] cell line was investigated in vitro. JETL cells were irradiated with LPLI at 635nm and 780m wavelengths [energy density 9.174 J/cm[2], and assessed for the expression of HSP70 and HSP90 by flow cytometry after 24, 48 and 72 incubation time periods [ITPs]. At 24 hours ITP post-irradiation, control cultures showed that 10.7% of cells expressed HSP70, while LPLI cultures at 635nm and 780nm manifested a higher expression [32.1and 21.3%, respectively], and the difference was significant [P