Modulating heat shock proteins 70 and 90 expression by low power laser irradiation [635nm and 780nm] in jurkat E6.1 T-lymphocyte leukemia cell line

ABSTRACT

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 ITP, the three means were decreased but approximated [5.6, 4.9 and 6.2%, respectively], while at 72 hours ITP, they were markedly increased [45.2, 76.5 and 66.7%, respectively]. In contrast, HSP90 responded differently to LPLI. At 24 hours ITP, control cultures and 780nm cultures showed a similar expression [55.9 and 55.9%, respectively], but both means were significantly higher than that of 635nm cultures [24.0%]. No such difference was observed at 48 hours ITP, and at 72 hours ITP, control cultures and 635nm cultures shared approximated means [31.7 and 35.6%, respectively]; but both means were significantly higher than the observed mean in 780nm cultures [15.2%]. The results highlighted that HSP70 and HSP90 expression responded differently to LPLI in JETL cells; an observation that may pave the way for further investigations in malignant cells